Thank you for posting this video. You just helped a homeless Veteran keep his truck running (that provides heat) in the cold. This Thanksgiving, I give thanks to your post Sir.
I use the old GM wiring code for nearly every re-wire I do (car/truck), and they all have the "fusible link" at the Alternator & Starter. Like you showed, it's not a "fuse" its a smaller gauge wire that continues to the Alt & Starter. To be honest about it, I use the Speedway 22 circuit kit because at $200 it makes life so much easier, and a HUGE time saver over making one up myself. It's all built right into the kit & makes everything new (and easy to identify later). That being said, you find "fusible links" in weird places depending on brands. Take an '86 Jeep CJ7 for instance (I'm doing one right now). They use the Tachometer as 1 of their Fusible links. When bad things happen, they are designed to burn the Tach before the rest of the Jeep. Lot of Mopar (and other pre 65 cars) use the Amp Gauge as the link. So really you do, but they aren't always Fuses.
Thank you again for this video. There is so much crap on the internet. I became a big fan when I restored my '72 Camino during Covid. I just revisited this video because of my concerns about my current project car (Porsche 914). My problem is that the original battery power wires, both unfused, were over 12ft long running from the battery, in the trunk, to the ignition switch and front fuse panel via a central tunnel. To make this a bigger issue these wires ran right next to the rear wiring harness and two plastic fuel lines (common configuration of rear engine Porsche's). It's no surprise that these cars are notorious for catastrophic engine and interior fires. I knew this would be an issue so, like your Jeep, I fused these wires at the battery before they entered the central tunnel. I also ran insulated wire sleeves and changed the fuel lines to full length stainless steel lines to reduce the risk of fire. I needed to review your video on wiring to reconfirm what I should do regardless of what the "experts" said. Thanks again Chris.
grounding the alt is another car audio thing, the alt is already grounded by being bolted to the engine but what people do is run another ground wire from that point to battery due the current increasing ( usually added a more powerful alt ), they even add more grounding wire to the chassi ,I have heard terms like "bottle neck" referring to the lack of grounding wires. Great video by the way. You are the person who taught me with your videos what a relay is and why we use them thank you so much!
Actually not a car audio only thing. Newer diesels been known to do it because the high draw modules are voltage sensitive also when a lot of accessories (lights and aux hvac ect) are installed it is recommended as well, typical with off road vehicles like overlanders.
Sir, you are very intelligent. And you’re correct there’s no in-line fuse that goes to the alternator but some have a fuse-able link so that it can charge the electrical components. It is at the moment in Harding at Palms my beautiful wife change alternator bring battery and still not able to charge the battery for the next time I use a vehicle so it’s gonna be confusing but your video helps me out a lot to get a general idea of like grounding and all of that such thing I guess cause I am 😂beginner.
hey chris ive been trying to cleanup the surface rust in the trunk of my 72, what would u recommend process and grit wise to cleanup the inside of the quarters and trunk etc? Thank you!! big fan lol
On my 54 chevy pickup, which is all steel, i fuse everything individually. Any cable may get in contact with the body by any reason. And in that event i dont get stock because i only may loose one element. And i may be able to continue running for next stop maintenance. Everything like you said must be fused. I wire my truck myself without any previous experience thanks to your advise. Even on a steel box like my truck i feel electrically safe thanks ti my fuse block.
Thank you for this wonderful video. One question, there are 2 more smaller wires to Ign switch and alternator dash light. Do these need to be fused? What Amps?
Hey man. Love the video! I have a 80 corolla I'm doing a gm alternator upgrade and it looks like the factory positive battery cable is split to my main fusebox. Is it OK to hook it up or not. Thanks
My 2020 Chevy express has a fusible links on both 6ga wires going to the starter and the alternator. The fusible links are at the BATTERY, the power source that you can’t shut off by turning the ignition off. I can shut the alternator down, besides look at the 14 ga solid wire inside your alternator. How much do you think that will handle before it melts. That is your fusible link on the alternator end.
I got a quick questions. My ground for my alternator is fused with fusible link. So are you saying dont need if? Or its jus something thats done buy choice? I know the video is old but if you see it could you get back with me.
Thanks for insight, I put a 1 gauge wire from battery to starter solenoid and at starter solenoid terminal it goes into I think a 2 gauge wire that leads to everything aside from starter. Wondering if this 1 gauge is overkill and should be reduced to something smaller so it would have battery chance of severing in event of catastrophic short?
If you were to put in a link at the alternator, seems if it blows it protects only the alternator and the length of wire running to the battery would still be hot and unprotected. Would it be best to put fusible links at both ends (alt, bat)?
We’ll explain thanks for the help I have a 79 c20 and am having problem with the charging system and this fusible link goes on the starter there 2 put new alternator and brand new battery and still not charging hopefully it’s that I won’t do it I don’t have the tools for the moment will have to take to the electric , since I need smog aready and don’t want truck leave me at the smog station 😂 thanks again for the class ,
Hey man i just wanted to let you know i actually just dissasembled my battery harness in my 04 jeep wj 4.0 doing a diy big 3 and that fusable link is a 10 ga fusable link actually to the alternator input to the fuseblock thats crimped together with the battery cable the starter is that secondary wire off the battery that runs down with the harness to the starter as some starters can actually pull 250 amps so thats the wire thats not normally fused. You cant tell without pulling the tape and split loom off everything.
i checked mine like 10 times.. but thanks.. i will look at it again.. make a video on that.. i want to see it.. i have no plans on upgrading any wiring on my jeep but i would like to see what you do to yours..
I agree with most of your comments but fuses and fusible links are there to protect wires. Not humans or components. In your example of fusing the alternator, the fuse would be on the wrong end of the wire offering no protection for the cable before that fuse. Should that cable contact the frame ground either through chaffing or possibly an accident, it would still be a direct short. The difference between a fusible link and a fuse is the link offers surge protection, something the 300 CCA battery can produce. The reason there is seldom a fuse in the alternator feed is the alternator itself is the weakest link. Generally the diodes. By the way, aircraft do fuse the battery using large 200 or even 300-Amp fuse blocks. So it is possible if one chose to do it. They are generally mounted as close to the battery as possible. These blocks and fuses can be purchased through any aircraft supply. They are about the size of a pack of gum.
To put it in short though are there any disadvantages to fusing an alternator to battery connection? Beyond premature loss of power due to the fuse blowing.
what are you trying to protect with that fuse? the point of the video is showing you don’t need a fuse unless you are running huge power to something like in car audio. what are you running power to that even needs a fuse at the alternator? Just buy a factory replacement cable there is nothing that needs an upgrade on a stock vehicle
@@chriscraft77022 the factory cable is fused is what I'm trying to say. My only concern would be if the alternators internal voltage regulator went bad but that's voltage not amps so maybe a fuse wouldn't do anything. Worst case a fuse is a harmless safety precaution. I'd rather not buy a factory replacement cable for a vehicle from 1991. Also I'd have to follow it through the main loom. You still fail to state the disadvantages of fusing an alternator which I believe there are none if done properly. Your video title should be don't fuse your stock connection to your alternator for no reason. If the wire is prone or likely to grounding out for any reason there is no harm in fusing it. If your confident then sure you don't need to. Your just arguing the point that the suggestion is a waste of money and yes most of the time it is but when you need it most its really just a safety precaution so install it with that in mind on what your trying to save. Me I'm trying to prevent putting a 4ga power lead to my battery and waiting for it to ground out on the chassis and start welding or damage my battery severely, reducing the lifespan of the part.
I'll agree that the fuse I have installed will probably never see any relevancy but I know it's there Incase shit hits the fan. Electricity isn't always as predictable as we'd like it to be.
I had just picked up my brother's Chevelle from the shop and was driving home when something shorted and caught some of his school papers on fire under the back seat. Pulled over and pulled all the burning material out. Hands were toasty but the Chevelle was ok.
My battery sparks when I have the alternator wired with an unfused 10 awg wire running to the junction block. Weirdly enough I've replaced and soldered 80 percent of the sun damaged wires. And I have my purple wire to the S terminal.. should I run that purple to the junction box?
no.. and you have a big problem .. does your battery have those crappy terminals that you clamp the wire in? If so clean all that crap up.. a battery should never spark … a fuse doesn’t have anything to do with that
@@chriscraft77022 No I would not dare I know and would never use those. I have commercial 2 awg power and 0 awg ground cables that I've purchased from tractor supply for around 35 bucks each
You need to check the ground on the alternator case.. it could be dirty or painted.. check resistance you should have .01 on alternator case.. I don’t know why it would be arcing at the battery
I see your logic, not to contradict but my Honda has a 60amp fuse for the "battery" circuit. I was brought here because I'm trying to learn more about upgrading my original battery to alt cable because my old one is worn out so to speak. I just put a 60 amp fuse on the 4 gauge wire I connected between my bat and alt positive terminals and it's a 60 amp alternator so I think I'm safe. It matches the original fuse for the full circuit. It's safe to assume my connection will take less load than the original circuit because I just have the two points connected and I'm assuming there's more connected to the battery fuse, or the fuse is to protect the car from the potential of the battery.
yes that's proper do you wanna know why.. So if you jumpstart your battery wrong and put positive the negative negative to positive you blow the fuse and it doesn't blow your PCM you still could , but it's more protected
One thing I have wondered about is if it's possible/probable for an alternator to internally short out. I have never seen or heard of this happening, but plenty of cars do fuse the alternator power wire for whatever reason even if its run in a way where it would be virtually impossible for it to short out. Whether that's to protect the wiring if the alternator shorts out internally or perhaps just for added safety if someone connects the battery backwards I don't know.
i have an 80s mercury cougar and the post on the back of the alt is loose and sparks like a hot damn when the cars running and drops the voltage to 9 volts, yes its possible
@@TBO207 Interesting, I never saw that before. Is the alternator internally shorted or just not working? Or is the loose post shorting against the case?
I'm only two months into myself education on this, but isn't an alternator grounded by the casing to the engine? And the remainding current after what is used to run the vehicle is fused in case the fuses of interior circuits fail. If my 20A fuse blows on my blower motor and heater the current from there suddenly needs to go somewhere else doesn't it? Would that not drastically increase the amperage past what some batteries if not all can handle for charging? This is exactly what I'm trying to figure out right now is that I don't understand how much amperage a battery can take as far as charging I just know that it has to remain at the same voltage with I don't get if you increase the wire size. There's a disconnect somewhere for me and it's in my brain. I can't wait to never rewire anything from scratch again
I'm actually at the tail-end of rewiring the entire truck which is an 85 Toyota. I've been in the thick of this for 2 months. Two months straight under the hood I'm still confused on the fundamentals of battery charging. My disability and having nobody to walk me through it step by step while holding my hand is why I'm lost.
The alternator is grounded to the engine block, and there should be a ground cable from the block to the battery because the block itself is not grounded to the frame. The rest of your questions are a little complicated to answer. Current is determined by the load (heater), not the alternator or battery. So if the fuse blows, it just means that the alternator or battery don't have to supply as much current anymore. So there is no extra current that needs to go anywhere. The battery will only take what it needs to charge, so you are not going to damage it. The important part about charging a battery is the voltage of the alternator. Wire sizes play 2 rolls. The resistance of a wire decreases with the size of the wire. So a small diameter wire has more resistance than a big diameter wire. The resistance of the wire is what causes it to heat up. How hot it gets is basically how much power it is taking and is directly proportional to the resistance of the wire and the current. That's why when you have higher current you want bigger wires (lower resistance). The other part is that all the heat in the wires drops the voltage. Since you don't want a lot of voltage drop between the alternator and the battery, you want a large wire connecting them.
What happens if your car is in a collision and let's say the unfused battery-alternator wire is crushed against the frame (making contact) which completes a circuit to the negative battery terminal which is grounded on the chassis? Fire?
it arcs like a welder and usually burns the wire in two in a fraction of a second.. if there is anything around it that can burn, yes... why don’t they fuse the battery from the factory??? that is the point
@@chriscraft77022 thanks for the reply. I have my battery in the trunk and I'm running a 120A fuse before the starter. Hopefully that pops before the arc welder situation arises.
the reason I didn’t bring that up is because my 17 Camaro has a factory battery in the trunk with no fuses .. and it is an SS convertible ... that car has a lot of flammable stuff in it... and your fuse should be on the positive battery post if you want it to protect anything during a wreck..
My friend owns an auto body shop, a Jeep came in late they couldn't get the hood open because it was crushed. So he just left it for the next day. Overnight you could see some Sparks on the camera twice, like 5 min apart then it's smoldered for about would look like a 20 min to a half hour. Then caught fire. Burn his whole shop and everything in it and every car in it. The bad part was he had just changed his insurance company 3 months before. They sent so many inspectors and forensics guys even though there was video proof of how the fire started. The insurance company gave him a real hard time for his payout.
Great video. But one question. Why use a fuseable link in place of let’s say a 200amp ANL. If one pops while I’m snow plowing, it’s so much easier to just throw another fuse in then to make another fuseable link
if you are popping big fuses you have a serious wiring problem. I have never had to replace a fused link… I have never used a snow plow but if it does pop them every now and then a fused link would be stupid.,, I have just never seen anything that “pops” fuses that was wired correct
I’m not popping fuses, but if I did pop a fuse in the middle of a storm because of the surge with the plow, lifting heavy, wet snow up, the salter on, the vibrator on lights, heat, radio, camera systems… let’s say something did pop, now to do a fusible link as opposed to a fuse that just doesn’t make sense to me.
oh dang.. I don’t know anything about snow plows… so that machine draws power constantly… the truth is a fused link can take more than a correct sized fuse.. a fuse pops in a second.. where a fused link heats up .. there is a debate but I just use what the factory put on.. so what does your plow have on it?
Fusible links are cheap. That’s why manufactures use them over circuit breakers, ANL or Mega fuses. That keeps more money in their suit pockets in stock portfolios. It’s all about greed and corruption in the USA. No integrity.
i was doing a fuel pump relay kill switch….85 is a ground,87 is 10 gauge sodered to fuel pump positive wire,86 is to toggle switch,others side goes to positive on battery,30 also goes to battery…..switch is turning on and off but car keeps starting whether i turn toggle switch on or off……not sure what i did wrong this is for BMW e46 2001 330xi
Most cars the battery goes directly to the fuse box within a foot or 2 And there's an actual separate fuse for the battery main circuit it goes from my fuse box too The alternator. Most cars they dont go directly to the alternator from the battery.. It usually goes from the alternator to the fuse box then to the battery, my alternator has 110 AMP fuse on it in the Engine bay's fuse box.. My car has 2 different fuse boxes one in the interior one in engine bay... If you're going to use and unfused wire from battery to alternator I would fuse it if it's more than a 3 foot run and less then 1/0 wire.. let's say it's a 4 foot run of 1/0 wire you should be OK..to not fuse it... with a stock alternator..
Hey Chris, I bought the switch & wire, per your kill switch video. Been waiting circa 2 years for your promised Part II. You have a very large # of comments and replies bugging you to follow thru on that. Are you ever going to follow thru on that? Or should we research other Channels for something similar? It's past time to either shit or get off the pot on that Part II. 😎
im not working on the chevelle now.. i dont know what vehicle you are working on so i cant tell you how to wire it up.. you need a 4 pin relay to ground out the horn button under the dash when it is energized if you dont want to run a wire back up to the horns.. i should be working on the chevelle again in the fall... SORRY
@@chriscraft77022 Your courtesy of a reply is a positive in lieu of your part 2 video. I intend to proceed ASAP to install my 20 amp single pole, double throw switch (10 gauge wire) to my 1984 MBZ SEC. based upon your Kill Switch video Part 1 diagram including the single wire from the switch to the horn in your diagram. If I am missing anything here please let me know before I get into this project. Thank you Chris.
You cant fuse the alternator wire, If you put a fuse at the alt and if it that blows the battery still is powering the line, if you put a fuse at the batt and if that blows the alt is still powering the line. So two fusible links maybe in a rewire have seen it in a stock factory car.
The battery should always be fused main reason because people sometimes mix the jumper cables with the battery and then you fry the PCM and ECM... You should always fuse your positive lead on any type of accessory one accessory that they usually don't but they do isolate is the starting system
that’s for the efi I have a 78 280z too.. the alternator fused link is in the little plastic covered part on the passenger fender . The smaller black one
@@chriscraft77022 yeah, sorry, I wasn’t very specific. The fusible link for the alternator is one of the four links under the plastic covers. 80amp link I believe
If you have a 120A alternator then you would fuse it accordingly (80A would probably be fine if you understand what it takes to blow a fuse) considering the alternator produces current and not drawing it from the battery. The funny part is what does draw such a load is the starter and yours has a fusible link on it? Weird. However are you certain the alternator wire isn't the one with the fusible link and the straight wire isn't going to the starter?
I agree and am also confused by this. If the starter draws more than 300 amps, I don’t understand how the fusible link going to the starter doesn’t blow.
@@MyTH-camchannel.995 because it takes a much higher load to blow it instantaneously. It takes 10x the rating at around 1 full second for a non delay fuse. For a delay rated fuse it can take up to 100x the rating for it to blow instantaneously.
@@commonsenseisdeadin2024 I think I see. So if I were to crank the starter continuously for 30 seconds or a minute (or theoretically longer/long enough to heat up the circuit), the fusible link would maybe/probably blow...?
@@MyTH-camchannel.995 a ANL fuse has a interrupt rating of 2700A. My assumption is that is the minimum it needs to be certified by UL or RoHS or SAE 🤷♂️ again that's my assumption. Time delay has 5000A plus. That is from a quick search I did.
@@MyTH-camchannel.995 starter will probably over heat first and that's if it does have a fusible link on the starter wire. But a starter should only pull 200 give or take how many cylinders and compression ratio. A fusible link is just a thinner gauge wire, the length determines the rating so longer it is the weaker it is.
18g wire is NOT appropriate for anything running running 5 or more amps. 16g high heat wire is the minimum you should use. 14g high heat wire is my preference. That 18g can start to heat and even melt before your fuse blows.
@@chriscraft77022 that was the red fused wire from the stereo in the explanation. I’ve seen so many people spend time adding fuses to cheap wire and the wire can’t handle the load and burns out before the fuse blows. Or the people that keep blowing fuses and just decide to replace a 10amp fuse with 15 or 20amp.
![[TH] 2024 PMSL SEA GF D3 | Summer | มาร่วมเป็นพยาน กับวินาทีแชมป์!](http://i.ytimg.com/vi/JCYvEsFlwx8/mqdefault.jpg)
Thank you for posting this video. You just helped a homeless Veteran keep his truck running (that provides heat) in the cold. This Thanksgiving, I give thanks to your post Sir.
I use the old GM wiring code for nearly every re-wire I do (car/truck), and they all have the "fusible link" at the Alternator & Starter. Like you showed, it's not a "fuse" its a smaller gauge wire that continues to the Alt & Starter. To be honest about it, I use the Speedway 22 circuit kit because at $200 it makes life so much easier, and a HUGE time saver over making one up myself. It's all built right into the kit & makes everything new (and easy to identify later).
That being said, you find "fusible links" in weird places depending on brands. Take an '86 Jeep CJ7 for instance (I'm doing one right now). They use the Tachometer as 1 of their Fusible links. When bad things happen, they are designed to burn the Tach before the rest of the Jeep. Lot of Mopar (and other pre 65 cars) use the Amp Gauge as the link.
So really you do, but they aren't always Fuses.
Your videos are great Chris. Good job
man finally someone that was detailed with the fusible link
Thank you again for this video. There is so much crap on the internet. I became a big fan when I restored my '72 Camino during Covid. I just revisited this video because of my concerns about my current project car (Porsche 914). My problem is that the original battery power wires, both unfused, were over 12ft long running from the battery, in the trunk, to the ignition switch and front fuse panel via a central tunnel. To make this a bigger issue these wires ran right next to the rear wiring harness and two plastic fuel lines (common configuration of rear engine Porsche's). It's no surprise that these cars are notorious for catastrophic engine and interior fires. I knew this would be an issue so, like your Jeep, I fused these wires at the battery before they entered the central tunnel. I also ran insulated wire sleeves and changed the fuel lines to full length stainless steel lines to reduce the risk of fire. I needed to review your video on wiring to reconfirm what I should do regardless of what the "experts" said. Thanks again Chris.
grounding the alt is another car audio thing, the alt is already grounded by being bolted to the engine but what people do is run another ground wire from that point to battery due the current increasing ( usually added a more powerful alt ), they even add more grounding wire to the chassi ,I have heard terms like "bottle neck" referring to the lack of grounding wires. Great video by the way. You are the person who taught me with your videos what a relay is and why we use them thank you so much!
Actually not a car audio only thing. Newer diesels been known to do it because the high draw modules are voltage sensitive also when a lot of accessories (lights and aux hvac ect) are installed it is recommended as well, typical with off road vehicles like overlanders.
you have to be careful with adding ground wires. Too many can actually cause ground loops which can cause problems for electronics and such.
Awesome video i finally know how the fusible link is hooked up
Sir, you are very intelligent. And you’re correct there’s no in-line fuse that goes to the alternator but some have a fuse-able link so that it can charge the electrical components. It is at the moment in Harding at Palms my beautiful wife change alternator bring battery and still not able to charge the battery for the next time I use a vehicle so it’s gonna be confusing but your video helps me out a lot to get a general idea of like grounding and all of that such thing I guess cause I am 😂beginner.
hey chris ive been trying to cleanup the surface rust in the trunk of my 72, what would u recommend process and grit wise to cleanup the inside of the quarters and trunk etc? Thank you!! big fan lol
On my 54 chevy pickup, which is all steel, i fuse everything individually.
Any cable may get in contact with the body by any reason. And in that event i dont get stock because i only may loose one element. And i may be able to continue running for next stop maintenance. Everything like you said must be fused. I wire my truck myself without any previous experience thanks to your advise.
Even on a steel box like my truck i feel electrically safe thanks ti my fuse block.
Thank you for this wonderful video. One question, there are 2 more smaller wires to Ign switch and alternator dash light. Do these need to be fused? What Amps?
hi what would be the size of the fuse if we use 6 gauge from battery to alternator having 100A or 80A?
Hey man. Love the video! I have a 80 corolla I'm doing a gm alternator upgrade and it looks like the factory positive battery cable is split to my main fusebox. Is it OK to hook it up or not. Thanks
Thanks man, great vid!
I'm my '98 Suburban, the 8 guage alternator charging wire goes straight to the +B. It also has a 10 A fusible link. This is off of a 105A juicer
Thanks Chris, my warm ground it must be my shut off device.
My 2020 Chevy express has a fusible links on both 6ga wires going to the starter and the alternator. The fusible links are at the BATTERY, the power source that you can’t shut off by turning the ignition off. I can shut the alternator down, besides look at the 14 ga solid wire inside your alternator. How much do you think that will handle before it melts. That is your fusible link on the alternator end.
If you upgrade alternator for audio, and you should of course upgrade the B+ wire, make sure to also upgrade a ground to engine block.
I got a quick questions. My ground for my alternator is fused with fusible link. So are you saying dont need if? Or its jus something thats done buy choice? I know the video is old but if you see it could you get back with me.
Big trucks high amp alternators generally have a separate ground wire running to them.
Thanks for insight, I put a 1 gauge wire from battery to starter solenoid and at starter solenoid terminal it goes into I think a 2 gauge wire that leads to everything aside from starter. Wondering if this 1 gauge is overkill and should be reduced to something smaller so it would have battery chance of severing in event of catastrophic short?
no, that’s fine… people don’t t go oversized because of the cost
Great information!!
Another practical vid
Fuse the wire to starter solenoid, or the starter main feed wire?
If you were to put in a link at the alternator, seems if it blows it protects only the alternator and the length of wire running to the battery would still be hot and unprotected. Would it be best to put fusible links at both ends (alt, bat)?
yes i was thinking the same thing because you have a power source at both ends
New sub great vid.
Thanks bro 🙏 🙌
We’ll explain thanks for the help I have a 79 c20 and am having problem with the charging system and this fusible link goes on the starter there 2 put new alternator and brand new battery and still not charging hopefully it’s that I won’t do it I don’t have the tools for the moment will have to take to the electric , since I need smog aready and don’t want truck leave me at the smog station 😂 thanks again for the class ,
Thank you you helped me
My Ford e250 caught on fire at the fuselinkwire and positive battery Spot ?.. going to the grounding spot front two bolts
Hey man i just wanted to let you know i actually just dissasembled my battery harness in my 04 jeep wj 4.0 doing a diy big 3 and that fusable link is a 10 ga fusable link actually to the alternator input to the fuseblock thats crimped together with the battery cable the starter is that secondary wire off the battery that runs down with the harness to the starter as some starters can actually pull 250 amps so thats the wire thats not normally fused. You cant tell without pulling the tape and split loom off everything.
i checked mine like 10 times.. but thanks.. i will look at it again.. make a video on that.. i want to see it.. i have no plans on upgrading any wiring on my jeep but i would like to see what you do to yours..
I have a wiring question for you is there a way to email you. Let know thanks
Hi Chris, I have a Chevelle over charge problem and sure could use your help. Would you be interested in some one on one time? $$$
I agree with most of your comments but fuses and fusible links are there to protect wires. Not humans or components. In your example of fusing the alternator, the fuse would be on the wrong end of the wire offering no protection for the cable before that fuse. Should that cable contact the frame ground either through chaffing or possibly an accident, it would still be a direct short.
The difference between a fusible link and a fuse is the link offers surge protection, something the 300 CCA battery can produce. The reason there is seldom a fuse in the alternator feed is the alternator itself is the weakest link. Generally the diodes.
By the way, aircraft do fuse the battery using large 200 or even 300-Amp fuse blocks. So it is possible if one chose to do it. They are generally mounted as close to the battery as possible. These blocks and fuses can be purchased through any aircraft supply. They are about the size of a pack of gum.
To put it in short though are there any disadvantages to fusing an alternator to battery connection? Beyond premature loss of power due to the fuse blowing.
what are you trying to protect with that fuse? the point of the video is showing you don’t need a fuse unless you are running huge power to something like in car audio. what are you running power to that even needs a fuse at the alternator? Just buy a factory replacement cable there is nothing that needs an upgrade on a stock vehicle
@@chriscraft77022 the factory cable is fused is what I'm trying to say. My only concern would be if the alternators internal voltage regulator went bad but that's voltage not amps so maybe a fuse wouldn't do anything. Worst case a fuse is a harmless safety precaution. I'd rather not buy a factory replacement cable for a vehicle from 1991. Also I'd have to follow it through the main loom. You still fail to state the disadvantages of fusing an alternator which I believe there are none if done properly. Your video title should be don't fuse your stock connection to your alternator for no reason. If the wire is prone or likely to grounding out for any reason there is no harm in fusing it. If your confident then sure you don't need to. Your just arguing the point that the suggestion is a waste of money and yes most of the time it is but when you need it most its really just a safety precaution so install it with that in mind on what your trying to save. Me I'm trying to prevent putting a 4ga power lead to my battery and waiting for it to ground out on the chassis and start welding or damage my battery severely, reducing the lifespan of the part.
I'll agree that the fuse I have installed will probably never see any relevancy but I know it's there Incase shit hits the fan. Electricity isn't always as predictable as we'd like it to be.
I had just picked up my brother's Chevelle from the shop and was driving home when something shorted and caught some of his school papers on fire under the back seat. Pulled over and pulled all the burning material out. Hands were toasty but the Chevelle was ok.
My battery sparks when I have the alternator wired with an unfused 10 awg wire running to the junction block. Weirdly enough I've replaced and soldered 80 percent of the sun damaged wires. And I have my purple wire to the S terminal.. should I run that purple to the junction box?
no.. and you have a big problem .. does your battery have those crappy terminals that you clamp the wire in? If so clean all that crap up.. a battery should never spark … a fuse doesn’t have anything to do with that
@@chriscraft77022 No I would not dare I know and would never use those. I have commercial 2 awg power and 0 awg ground cables that I've purchased from tractor supply for around 35 bucks each
You need to check the ground on the alternator case.. it could be dirty or painted.. check resistance you should have .01 on alternator case.. I don’t know why it would be arcing at the battery
Chris if you don't fuse the ground then why does my ground on battery get warm during starting?
clean it.. it’s not making good contact.. check for resistance.. the ground does not get hot
I see your logic, not to contradict but my Honda has a 60amp fuse for the "battery" circuit. I was brought here because I'm trying to learn more about upgrading my original battery to alt cable because my old one is worn out so to speak. I just put a 60 amp fuse on the 4 gauge wire I connected between my bat and alt positive terminals and it's a 60 amp alternator so I think I'm safe. It matches the original fuse for the full circuit. It's safe to assume my connection will take less load than the original circuit because I just have the two points connected and I'm assuming there's more connected to the battery fuse, or the fuse is to protect the car from the potential of the battery.
yes that's proper do you wanna know why.. So if you jumpstart your battery wrong and put positive the negative negative to positive you blow the fuse and it doesn't blow your PCM you still could , but it's more protected
One thing I have wondered about is if it's possible/probable for an alternator to internally short out. I have never seen or heard of this happening, but plenty of cars do fuse the alternator power wire for whatever reason even if its run in a way where it would be virtually impossible for it to short out. Whether that's to protect the wiring if the alternator shorts out internally or perhaps just for added safety if someone connects the battery backwards I don't know.
i have an 80s mercury cougar and the post on the back of the alt is loose and sparks like a hot damn when the cars running and drops the voltage to 9 volts, yes its possible
@@TBO207 Interesting, I never saw that before. Is the alternator internally shorted or just not working? Or is the loose post shorting against the case?
@@averyalexander2303 the internals of the alternator are shorting out it melted the charge wire from the alt but it got me home lol
@@TBO207 Wow that's crazy, I never heard of that before. Probably a good idea to fuse alternators then.
I'm only two months into myself education on this, but isn't an alternator grounded by the casing to the engine? And the remainding current after what is used to run the vehicle is fused in case the fuses of interior circuits fail. If my 20A fuse blows on my blower motor and heater the current from there suddenly needs to go somewhere else doesn't it? Would that not drastically increase the amperage past what some batteries if not all can handle for charging? This is exactly what I'm trying to figure out right now is that I don't understand how much amperage a battery can take as far as charging I just know that it has to remain at the same voltage with I don't get if you increase the wire size. There's a disconnect somewhere for me and it's in my brain. I can't wait to never rewire anything from scratch again
I'm actually at the tail-end of rewiring the entire truck which is an 85 Toyota. I've been in the thick of this for 2 months. Two months straight under the hood I'm still confused on the fundamentals of battery charging. My disability and having nobody to walk me through it step by step while holding my hand is why I'm lost.
The alternator is grounded to the engine block, and there should be a ground cable from the block to the battery because the block itself is not grounded to the frame.
The rest of your questions are a little complicated to answer. Current is determined by the load (heater), not the alternator or battery. So if the fuse blows, it just means that the alternator or battery don't have to supply as much current anymore. So there is no extra current that needs to go anywhere. The battery will only take what it needs to charge, so you are not going to damage it. The important part about charging a battery is the voltage of the alternator. Wire sizes play 2 rolls. The resistance of a wire decreases with the size of the wire. So a small diameter wire has more resistance than a big diameter wire. The resistance of the wire is what causes it to heat up. How hot it gets is basically how much power it is taking and is directly proportional to the resistance of the wire and the current. That's why when you have higher current you want bigger wires (lower resistance). The other part is that all the heat in the wires drops the voltage. Since you don't want a lot of voltage drop between the alternator and the battery, you want a large wire connecting them.
What happens if your car is in a collision and let's say the unfused battery-alternator wire is crushed against the frame (making contact) which completes a circuit to the negative battery terminal which is grounded on the chassis? Fire?
it arcs like a welder and usually burns the wire in two in a fraction of a second.. if there is anything around it that can burn, yes... why don’t they fuse the battery from the factory??? that is the point
@@chriscraft77022 thanks for the reply. I have my battery in the trunk and I'm running a 120A fuse before the starter. Hopefully that pops before the arc welder situation arises.
the reason I didn’t bring that up is because my 17 Camaro has a factory battery in the trunk with no fuses .. and it is an SS convertible ... that car has a lot of flammable stuff in it... and your fuse should be on the positive battery post if you want it to protect anything during a wreck..
My friend owns an auto body shop, a Jeep came in late they couldn't get the hood open because it was crushed. So he just left it for the next day. Overnight you could see some Sparks on the camera twice, like 5 min apart then it's smoldered for about would look like a 20 min to a half hour. Then caught fire. Burn his whole shop and everything in it and every car in it. The bad part was he had just changed his insurance company 3 months before. They sent so many inspectors and forensics guys even though there was video proof of how the fire started. The insurance company gave him a real hard time for his payout.
Old car, had the infused generator short out and roll smoke. Don't know if it would have burned the car or not.
💥💯👍
Great video. But one question. Why use a fuseable link in place of let’s say a 200amp ANL. If one pops while I’m snow plowing, it’s so much easier to just throw another fuse in then to make another fuseable link
if you are popping big fuses you have a serious wiring problem. I have never had to replace a fused link… I have never used a snow plow but if it does pop them every now and then a fused link would be stupid.,, I have just never seen anything that “pops” fuses that was wired correct
I’m not popping fuses, but if I did pop a fuse in the middle of a storm because of the surge with the plow, lifting heavy, wet snow up, the salter on, the vibrator on lights, heat, radio, camera systems… let’s say something did pop, now to do a fusible link as opposed to a fuse that just doesn’t make sense to me.
oh dang.. I don’t know anything about snow plows… so that machine draws power constantly… the truth is a fused link can take more than a correct sized fuse.. a fuse pops in a second.. where a fused link heats up .. there is a debate but I just use what the factory put on.. so what does your plow have on it?
Fusible links are cheap. That’s why manufactures use them over circuit breakers, ANL or Mega fuses. That keeps more money in their suit pockets in stock portfolios. It’s all about greed and corruption in the USA. No integrity.
i was doing a fuel pump relay kill switch….85 is a ground,87 is 10 gauge sodered to fuel pump positive wire,86 is to toggle switch,others side goes to positive on battery,30 also goes to battery…..switch is turning on and off but car keeps starting whether i turn toggle switch on or off……not sure what i did wrong this is for BMW e46 2001 330xi
@chriscraft the only thing i know is by watching your videos
Most cars the battery goes directly to the fuse box within a foot or 2 And there's an actual separate fuse for the battery main circuit it goes from my fuse box too The alternator. Most cars they dont go directly to the alternator from the battery.. It usually goes from the alternator to the fuse box then to the battery, my alternator has 110 AMP fuse on it in the Engine bay's fuse box.. My car has 2 different fuse boxes one in the interior one in engine bay... If you're going to use and unfused wire from battery to alternator I would fuse it if it's more than a 3 foot run and less then 1/0 wire.. let's say it's a 4 foot run of 1/0 wire you should be OK..to not fuse it... with a stock alternator..
How do you wire a startter
I have a video on that shows it wired on the table “testing a starter motor “
Hey Chris, I bought the switch & wire, per your kill switch video. Been waiting circa 2 years for your promised Part II.
You have a very large # of comments and replies bugging you to follow thru on that.
Are you ever going to follow thru on that? Or should we research other Channels for something similar?
It's past time to either shit or get off the pot on that Part II. 😎
im not working on the chevelle now.. i dont know what vehicle you are working on so i cant tell you how to wire it up.. you need a 4 pin relay to ground out the horn button under the dash when it is energized if you dont want to run a wire back up to the horns.. i should be working on the chevelle again in the fall... SORRY
@@chriscraft77022 Your courtesy of a reply is a positive in lieu of your part 2 video.
I intend to proceed ASAP to install my 20 amp single pole, double throw switch (10 gauge wire) to my 1984 MBZ SEC. based upon your Kill Switch video Part 1 diagram including the single wire from the switch to the horn in your diagram.
If I am missing anything here please let me know before I get into this project.
Thank you Chris.
You cant fuse the alternator wire, If you put a fuse at the alt and if it that blows the battery still is powering the line, if you put a fuse at the batt and if that blows the alt is still powering the line. So two fusible links maybe in a rewire have seen it in a stock factory car.
SUP CHRIS. I THOUGHT THE MOTOR WAS MECHANICALLY GROUNDED THRU THE FRAME?
not at all… I have an automotive grounds explained video
@@chriscraft77022 OH WOW CRAZY. I THOUGHT IVE READ CONTINUITY FROM THE BATTERY TO THE FRAME OF THE CAR?
there are grounding straps that connect them together. the rubber motor and transmission mounts do not conduct electricity.
@@chriscraft77022 THATS RIGHT. I UPGRADED THOSE WIRES TO 1/0 CAUSE I WANT TO EVENTUALLY THROW MY SUBWOOFER IN AND A BIGGER ALTERNATOR.
The battery should always be fused main reason because people sometimes mix the jumper cables with the battery and then you fry the PCM and ECM... You should always fuse your positive lead on any type of accessory one accessory that they usually don't but they do isolate is the starting system
have you ever opened the hood of a car?
@@chriscraft77022 Are you a certified Electrical Engineer?
@@sexyeyes6203 I guess auto makes like GM probably don’t hire electrical engineers right?
My 1978 280z has a fusible link by the battery for the alternator
that’s for the efi I have a 78 280z too.. the alternator fused link is in the little plastic covered part on the passenger fender . The smaller black one
@@chriscraft77022 yeah, sorry, I wasn’t very specific. The fusible link for the alternator is one of the four links under the plastic covers. 80amp link I believe
do you have videos? I just got mine in October 2022
If you have a 120A alternator then you would fuse it accordingly (80A would probably be fine if you understand what it takes to blow a fuse) considering the alternator produces current and not drawing it from the battery. The funny part is what does draw such a load is the starter and yours has a fusible link on it? Weird. However are you certain the alternator wire isn't the one with the fusible link and the straight wire isn't going to the starter?
I agree and am also confused by this. If the starter draws more than 300 amps, I don’t understand how the fusible link going to the starter doesn’t blow.
@@MyTH-camchannel.995 because it takes a much higher load to blow it instantaneously. It takes 10x the rating at around 1 full second for a non delay fuse. For a delay rated fuse it can take up to 100x the rating for it to blow instantaneously.
@@commonsenseisdeadin2024 I think I see. So if I were to crank the starter continuously for 30 seconds or a minute (or theoretically longer/long enough to heat up the circuit), the fusible link would maybe/probably blow...?
@@MyTH-camchannel.995 a ANL fuse has a interrupt rating of 2700A. My assumption is that is the minimum it needs to be certified by UL or RoHS or SAE 🤷♂️ again that's my assumption. Time delay has 5000A plus. That is from a quick search I did.
@@MyTH-camchannel.995 starter will probably over heat first and that's if it does have a fusible link on the starter wire. But a starter should only pull 200 give or take how many cylinders and compression ratio. A fusible link is just a thinner gauge wire, the length determines the rating so longer it is the weaker it is.
18g wire is NOT appropriate for anything running running 5 or more amps. 16g high heat wire is the minimum you should use. 14g high heat wire is my preference.
That 18g can start to heat and even melt before your fuse blows.
what was 18g in the video I don’t even remember
@@chriscraft77022 that was the red fused wire from the stereo in the explanation. I’ve seen so many people spend time adding fuses to cheap wire and the wire can’t handle the load and burns out before the fuse blows. Or the people that keep blowing fuses and just decide to replace a 10amp fuse with 15 or 20amp.
Mfr cost cutting measures, less fuses more coins in the stock holders pockets.
Really makes no sense to fuse link the starter....and then not to do the alternator. Seems backwards.
they must have made a mistake on mine cause some guy said his Jeep was fused to alt and not started