This is DIY automotive electrical gold! Thank you Eric and Paul! I learned a lot and have a much better understanding and basis to attack wiring issues besides just continuity and voltage tests. LOVE seeing you guys do videos together it's like two super hero's getting together for a video! PLEASE MORE MORE MORE of you two doing videos together!
Please Eric if at all possible make more electrical videos like this. I love how you can "dumb down" what Scanner Danner says for us non professionals (DIYers) Scanner Danner is smart, but you seem to have a more toned down way of explaining things. Together you guys do an amazing job. Thanks for the video.
An excellent video, as always. A nice sized bye of information for anyone, whether just getting started of looking for a bit of review. As a trainer, I often think we feel compelled to say what we are doing is basic for fear we might be boring someone. don't forget, if someone is watching this it's because they don't know and hopefully want to learn. For them it's not basic!
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Two of the best automotive technician/teachers on TH-cam Chris Fix and Eric O from south Main Street auto is also a good teacher you guys help me a lot on repairing vehicles at work god bless you two
ERIC, YOU ARE BOTH THE GREATEST ASSES TO OUR AUTOMOTIVE FIELD AND BETTER THAN THE BEST SOURCE OF PRACTIAL LOGIC IN EXPANATION. DANNER DOCUMENTED HIS KNOWLEDGE IN TEACHING AT THE SCHOOL ALSO AND PROVIDING HIS BOOK AS A GREAT SOURCE TO ALL TECHICIANS.
We are indeed living in great times - knowledge passed over with such a QUALITY - for free to everyone. I saw schools not doing 20% of what this video did.
Great video! I have very little experience on electrical systems; however, now that I watched your video, I understood perfectly well how ground side switched and power side switched function. I am working on a 2002 Lincoln LS, which has a nonworking or malfunctioning heating system. The A/C system does work, but when I select the heating, there is no hot air coming out. I am suspecting the heater control valve, which is ground side switched, to be bad. Thank you EricTheCarGuy and ScannerDanner for all your great videos. I am sorry if I don’t write very well, I am a Spanish speaking person. Thank you again.
When an awesome guy meets another awesome guy there cannot be anything less than AWESOMENESS :-) You both are a source of positive energy and just made my day. Thank you both! Live long and prosper (and stay dirty!)
I will buy his book to learn more about electrical circuit. The entire video is really interesting. Now, after I watch this video, I have less problem to deal with electrical issue. Less is not meaning nothing.
test light is great because it loads the circuit but just to find positive and negative wiring those "green,red leds testers" are a must i believe.. keep up the good work! love to see 2 great automotive legends together!!
test light is only half the battle. It will light on 6V which will give you a false reading. We had a module that went bad in the car and the test light came ON while testing making us think it had power when it only had 8V going to it. Always use a volt meter to verify 12V
I already had a pretty proficient understanding of how basic electricity works in a circuit. But after watching this video I feel I learned quite a bit more on top of everything I already knew. Thanks for the good lessons ETCG 👍
This video is super good !!! Every single person that is weak on electrical issues is gonna make huge gains after watching this. Just learning when ground side switching is "normal" helped me. Now you can apply it and do tricks , hehe
These collaborations are so great. The mutual admiration the two of you have for each other is beautiful. It adds something to the to the already wonderful education you are providing us. I will "like" any video with the both of you in it,
This was an amazingly simple video, a great starting foundation to understand whats going on. I was scratching my head only considering power activated circuits, ground activated circuits just allowed me to solve the puzzle!
Nice Video on explaining applied voltage. If no ground wire is found in a circuit it will be "flooded" with the voltage applied to the circuit. Even with many resistors in the circuit. Think of a winding river. If you place a dam in a river. The current flow goes to zero and all the winding turns and bends in the river get flooded out and overcome. You are essential cutting of the current flow. Those bends and turns in a river can be compared to resistors, but with a dam in place in the river (damn is like an open) they are overcome and now the water become static and the stored energy is the same from the power source to the dam (the open). Once the dam is removed (switch is closed) the circuit is complete and you get current flow...now the resistors (bends in the river) can effect current flow once again and you will energy losses (voltage drops) as the water flows around the bends. Very archaic way of explaining it but it helps to understand the basic theory.
+Oneguy If you test the side of the damn that has water flooded to it that is the positive side and you get applied voltage....if you test the side of the dam that has no water flow...that is the negative side and you will see zero. This my friends is known as my "DAMN THEORY" used it to teach military technicians for years. lol Hope I didn't confuse anyone.
I need to watch this a few more times to figure out if this is how a waste spark ignition coil pack works: I’ve long suspected that the ECU of my car alternates the lifting of ground and power to create the spark events, but now I will be able to learn/diagnose/backwards engineer the system prior to deciding to attempt to modify it. Thank you so much!
Determining circuit design, low side driver vs high side driver also determines the polarity at which your test light should be connected to in order to bypass components which I know Paul is notorious for doing(I do it all the time too) I just recently did it on a newer Honda(R17A) They use that starter cut relay with a yellow wire from the ignition switch energizing it. It is my preferred method for diagnosing compressor clutch coils as well. I am surprised no one has addressed Blind riveted TP sensors(Honda use to blind rivet their tps to the throttle body) A R&R video on those would be awesome. Great video guys.
Great video, same methods for looking for open ground. Don't forget Continuity tests of wires and parts. The more methods you have in your bag of tricks the better.
Thanks! Seriously both of you have helped a normal joe keep his kids cars running. I have learned much and really am enjoying something I was never exposed to .... working on cars. You have and are educating me ... much apprceciated
That was an EXCELLENT video! I've never quite understood how to determine, without a wiring diagram, which side is being switched until now. Thanks so much!! Great vid!
The other way to quickly identify which side is switched if both sides show ground is to look for ghost voltage after disconnecting the device. The side where your multimeter shows an unwavering zero volts will be the constant ground, and the switched open side will show ghost voltage.
ScannerDanner hey I'm a first year heavy duty and I'm having troubles and at work understanding back feeding like when you did it positive to the posiive side it still lite up could you explain it a bit better sometime?
VIheavyequipment To be clear, you are talking about when I had my test light connected to B+ and I touched on the positive side of the light bulb circuit with the light bulb still plugged in and the light bulb wire disconnected from B+. Right?
VIheavyequipment The short answer is this: If you are doing this test with a high ohm load in the circuit, the test light may not even light. If it is a low ohm load (like in the video) the test light lit brightly. Another twist, if using an LED test light, it would even light with a high ohm load in the circuit as it doesn't require the same current flow to light the LED as it does an incandescent bulb. This is one of the reasons I do not like the circuit testers with the red and green LEDs for power and ground ID. In this application, one of those tools would have lit green on that positive side of the circuit telling you it is a ground, when it is not. It is an un-switched or turned off power supply. There is so much to this. Hard to put all the variables into print.
First time I see a video of both you guys explaining the abc's. Awesome! Good clear and simple explanations. Surely a added value to all of us. Thumbs up. ;-)
ok i was watching scanners video on basic electrical review on his premium channel but this whole ground side switched and power side switched inputs and outputs i have to keep doing this till its second nature harder for some than others but i am power side switched and i am grounded so here i come in other words i understand it but i dont understand it which is frustrating its like im almost there but lack something hmmmm maybe knowledge
This is what I took away to determine if it’s ground side switched or power side switches. Put ground test lead (black wire ) on negative terminal of battery, next with the red test lead back probe the “light bulb” (circuit has to be off by the way) if you get a voltage on both wires then it’s ground side switched. If you get 0 voltage on both wires then it’s power side switched. Hope this made sense.
This will help me alot in the future,. I know some things about electricity but always scared to damage something in the car to find the source. thanks!
Great video! I really like these sort of videos, as I have a limited knowledge of electrical systems and really want to learn more. This was very easy to understand and had great info. You two are awesome as usual!
Excellent information! I have been wondering about the positive vs. negative side switching since I fixed my cars central locking remote system and read through some forum texts about central locking in general. Didn't quite understand how it works (got the remote control box installed anyway though), but this video really clears it up. Good work guys!
Great video! The only thing I would've added to the demonstration is another short piece of wire with alligator clips on each end to more accurately simulate a switch. The benefit to this would be identifying a positive side switch with just the volt meter by reading the switch's terminals. I think it also would've been nice to have a discussion about use cases for switching negative. But perhaps out of scope for this video.
When I was about 17 with my first car, negative side switching confussed the shit out of me until I drew a simple negative side switch diagram, then I got the light bulb moment. This should be a great smack in the face of logic for alot of people, great upload.
Hi Eric, just one thing that might be of interest, a 21 watt bulb on 12 volts draws approx. 2 amps, so by ohms law the filament of the bulb would be around , 6 ohms, now if you put an ohmmeter across that bulb it would read 0 ohms, try it, the only time the filament has 6 ohms is when it is red hot, if you could measure it then...other thing on mains electricity the switch is normally live side switched for safety reasons, so you don't get a shock from the bulb with it turned off....Fred in England.
g4vvq1983, it is true that resistance of an incandescent bulb rises as it heats up, but that bulb is not 0 ohms at room temperature. I think you need a more sensitive multimeter with sub-ohm range, that if you are at this stage of observation then the one you have is not versatile enough to help you proceed further in diagnostics. Many times you might have a bad electrical connection and it could help to see differences of an ohm, though another way through this issue is to measure the voltage drop across it (if you can power up the circuit).
13:38 instead of test lamp sir, you can use also multimeter by putting the one probe in positive terminal of battery and the other probe is for the wire you want to check.
one thing you might ad when using a meter. Is where you set your meter. A lot of people don't know anything about the meter like me. And i never really sure where to set my meter since there all kinds of different setting on it. You know maybe show your meter and show where you have it set so people know for sure. I know its something we all should know but always been something that confused me ty mike
you could use "ghost voltage" when testing for control wire(unplugged) during the positive side switch as an alternative rather than a test light? as one would have ghost voltage and the other would have 0V if im not mistaken
In electronics we call this sourcing (power side switching) and sinking (ground side switching). Its also good to understand most digital chips support more current when sinking.
Most digital chips don't handle enough current in automotive apps to matter, instead controlling mechanical or solid state relays, or a more integrated transistor switching which can be set up either way depending on the other requirements for the circuit.
To have two of the brightest internet technicians coming from a little college like Rosedale is a real feather in their cap. I wouldn't hesitate to pump their tires.
Eric, I really love watching your videos. What I would like to see is more that are done with a town and country/grand caravan. Mine needs a new heater core (leaks) and I need some expert advice on actually doing the repair.
another easy way to confirm a ground sid is siply set voltmeter to ohms and test each side of the harness to ground this can also verifit if your looking at a poor connection as your resistance will be higher
Great video, while I did learn most of this stuff some 15+ years ago in school, I have forgotten most of it because I have not used it in so long. It's nice to have a good refresher once in a while. Eric, really can't wait for some Fairlane videos, I know you want to work with sponsors and what not for upgrades, parts etc. But I would think there must be some videos you could do on it right now, like simple maintenance stuff.
Ah yes, Fairmont. I know the difference, just typed it wrong. My bad. I actually used to have a 86' Capri with the 5.0 HO and dual four barrels and edelbrock intake. It was a quick ride but a total rust bucket because it spent its life in New England with harsh winters. I ended up selling it from 2400 about 9 yearxs ago. I really regret iot now because I wish I had something to run at the track because I do not live far from Lebanon Valley drag strip. Anyways, cannot wait for some Fairmont videos. I'm not a Ford fanboy or anything (I like all makes, it's stupid not to) but I always loved the foxy body platform because of it's simplicity and the huge amount of parts and swapability. I mean hell, I could pout a F-150 dash in a mustang, heh. Keep em coming Eric.
You said that if you hook up your test light to positive side of the battery you just go ahead an touch the wires to find the ground side. Its true however your test light is not fused and it could fry the components on the negative side of the circuit.
so you know each other. Been watching the 2 of you individually. How did u 2 meet? Eric were u student at Rosedale? Was Paul your teacher? I consider both of you my personal teacher and it feels really good seeing both of you together. Now i'll just watch the vid. Congrats!
the best way to check for ground side switching is to check the switch. If you have power with the switch in the off position and nothing on both posts with the switch in the on position then you automatically know its ground switched because the load is burning the current
I have found some RAM trucks have a confusing combination of positive and negative switching. It can really complicate troubleshooting or installation of accessories.
Since electrons actually flow from the negative to the positive you can think of voltage as an electron vacuum. Another way to think of it would be as potential flow. The reason that you measure 0 volts on a power side switch is because the voltage between the battery ground and your other test lead is 0. There is no potential there. Whereas the voltage between the battery ground and the other test lead on a ground side switch would be 12 because there are 12 volts of difference, or potential, between the ground and positive on the battery.
Thanks guys. I really enjoyed that vid. One question that is bugging me… When you were negative side switching and you tested the negative side of the circuit, why didn't the light come on? Isn't the circuit being completed by the voltmeter because its connected to the ground?
Technically you're right, the meter is completing the circuit which is how it measures the voltage. However the series resistance of the meter (which is just a fancy way of saying how much current will flow through it at a given voltage) is extremely high in the order of 10 megaohms or more which means at 12 volts less than a microamp of current will flow through the meter which isnt enough current to heat up the filament in the lightbulb. This incredibly small amount of current is enough for the meter to accurately measure voltage
It's best to describe the grounding side as neg. side So as not to confuse students that associate it to AC current power side neutral side Since DC current flows neg to positive
One thing I have learned about electric and that is you really need to practice with experiments to remember everything or you will just forget it all eventually.
Hey Eric great vids. I just bought a 1947 plymouth with the original owners manual, It shows a positive ground system but the battery is hooked up as a negative system. Ir runs and all gauges work and horn but there are no lights anywhere. Is it due to the battery hook up or something else ?
This is DIY automotive electrical gold! Thank you Eric and Paul! I learned a lot and have a much better understanding and basis to attack wiring issues besides just continuity and voltage tests. LOVE seeing you guys do videos together it's like two super hero's getting together for a video! PLEASE MORE MORE MORE of you two doing videos together!
I just stumbled upon this vid eight years after publication. Much appreciation and respect to these men. Basic Gold!!!
Please Eric if at all possible make more electrical videos like this. I love how you can "dumb down" what Scanner Danner says for us non professionals (DIYers)
Scanner Danner is smart, but you seem to have a more toned down way of explaining things. Together you guys do an amazing job. Thanks for the video.
I think we make a great team as well. I'd be happy to do more of these.
+1
An excellent video, as always. A nice sized bye of information for anyone, whether just getting started of looking for a bit of review. As a trainer, I often think we feel compelled to say what we are doing is basic for fear we might be boring someone. don't forget, if someone is watching this it's because they don't know and hopefully want to learn. For them it's not basic!
Two of the best automotive technician/teachers on TH-cam Chris Fix and Eric O from south Main Street auto is also a good teacher you guys help me a lot on repairing vehicles at work god bless you two
ERIC, YOU ARE BOTH THE GREATEST ASSES TO OUR AUTOMOTIVE FIELD AND BETTER THAN THE BEST SOURCE OF PRACTIAL LOGIC IN EXPANATION. DANNER DOCUMENTED
HIS KNOWLEDGE IN TEACHING AT THE SCHOOL ALSO AND PROVIDING HIS BOOK AS A GREAT SOURCE TO ALL TECHICIANS.
We are indeed living in great times - knowledge passed over with such a QUALITY - for free to everyone. I saw schools not doing 20% of what this video did.
8 years old and .... thank you sir this is a great video!
Great video! I have very little experience on electrical systems; however, now that I watched your video, I understood perfectly well how ground side switched and power side switched function. I am working on a 2002 Lincoln LS, which has a nonworking or malfunctioning heating system. The A/C system does work, but when I select the heating, there is no hot air coming out. I am suspecting the heater control valve, which is ground side switched, to be bad. Thank you EricTheCarGuy and ScannerDanner for all your great videos. I am sorry if I don’t write very well, I am a Spanish speaking person. Thank you again.
When an awesome guy meets another awesome guy there cannot be anything less than AWESOMENESS :-)
You both are a source of positive energy and just made my day.
Thank you both!
Live long and prosper (and stay dirty!)
It's called a Bromance. hahahaha. Two smart bros.
I will buy his book to learn more about electrical circuit. The entire video is really interesting. Now, after I watch this video, I have less problem to deal with electrical issue. Less is not meaning nothing.
This is unbelievable 2 kings together.
Too much knowledge in 1 place I’ve learned a lo through this 2.
This is a great training video for technicians. This is better then most automotive shop training modules.
test light is great because it loads the circuit but just to find positive and negative wiring those "green,red leds testers" are a must i believe.. keep up the good work! love to see 2 great automotive legends together!!
test light is only half the battle. It will light on 6V which will give you a false reading.
We had a module that went bad in the car and the test light came ON while testing making us think it had power when it only had 8V going to it.
Always use a volt meter to verify 12V
Been studying to grasp auto electronics your presentation is superb and gained for me the lexicon of electronics trouble shooting thanks
Eric is a natural teacher. Very good
I already had a pretty proficient understanding of how basic electricity works in a circuit. But after watching this video I feel I learned quite a bit more on top of everything I already knew. Thanks for the good lessons ETCG 👍
This video is super good !!! Every single person that is weak on electrical issues is gonna make huge gains after watching this. Just learning when ground side switching is "normal" helped me. Now you can apply it and do tricks , hehe
Scanner Danner and Erick the Car Guy The Awesome PILLARS of Automotive Diagnostics!!!, Sharing is Caring.God Bless!!!
Paul and Eric, you are doing a comendable job on educating us in the Third World countries,, thanks a zillion once again.
These collaborations are so great. The mutual admiration the two of you have for each other is beautiful. It adds something to the to the already wonderful education you are providing us. I will "like" any video with the both of you in it,
Good to see two great guys together. Both are masters in their field.
Eric! watch your work constantly. Anglisski not speak. Your video without understanding the language is very clear and informative ..
This was an amazingly simple video, a great starting foundation to understand whats going on. I was scratching my head only considering power activated circuits, ground activated circuits just allowed me to solve the puzzle!
Nice Video on explaining applied voltage. If no ground wire is found in a circuit it will be "flooded" with the voltage applied to the circuit. Even with many resistors in the circuit. Think of a winding river. If you place a dam in a river. The current flow goes to zero and all the winding turns and bends in the river get flooded out and overcome. You are essential cutting of the current flow. Those bends and turns in a river can be compared to resistors, but with a dam in place in the river (damn is like an open) they are overcome and now the water become static and the stored energy is the same from the power source to the dam (the open). Once the dam is removed (switch is closed) the circuit is complete and you get current flow...now the resistors (bends in the river) can effect current flow once again and you will energy losses (voltage drops) as the water flows around the bends. Very archaic way of explaining it but it helps to understand the basic theory.
+Oneguy If you test the side of the damn that has water flooded to it that is the positive side and you get applied voltage....if you test the side of the dam that has no water flow...that is the negative side and you will see zero. This my friends is known as my "DAMN THEORY" used it to teach military technicians for years. lol Hope I didn't confuse anyone.
I need to watch this a few more times to figure out if this is how a waste spark ignition coil pack works: I’ve long suspected that the ECU of my car alternates the lifting of ground and power to create the spark events, but now I will be able to learn/diagnose/backwards engineer the system prior to deciding to attempt to modify it. Thank you so much!
Determining circuit design, low side driver vs high side driver also determines the polarity at which your test light should be connected to in order to bypass components which I know Paul is notorious for doing(I do it all the time too) I just recently did it on a newer Honda(R17A) They use that starter cut relay with a yellow wire from the ignition switch energizing it. It is my preferred method for diagnosing compressor clutch coils as well. I am surprised no one has addressed Blind riveted TP sensors(Honda use to blind rivet their tps to the throttle body) A R&R video on those would be awesome. Great video guys.
Great video, same methods for looking for open ground. Don't forget Continuity tests of wires and parts. The more methods you have in your bag of tricks the better.
Thanks! Seriously both of you have helped a normal joe keep his kids cars running. I have learned much and really am enjoying something I was never exposed to .... working on cars. You have and are educating me ... much apprceciated
That was an EXCELLENT video! I've never quite understood how to determine, without a wiring diagram, which side is being switched until now. Thanks so much!! Great vid!
Mr. ERIC thanks for setting the stage on this subject
Outstanding video on clueing us on two wires and which way did they go
Still a great video!!!! So much better to see this done practically than just learning the theory. Thanks guys!
The other way to quickly identify which side is switched if both sides show ground is to look for ghost voltage after disconnecting the device. The side where your multimeter shows an unwavering zero volts will be the constant ground, and the switched open side will show ghost voltage.
good tip!
ScannerDanner hey I'm a first year heavy duty and I'm having troubles and at work understanding back feeding like when you did it positive to the posiive side it still lite up could you explain it a bit better sometime?
VIheavyequipment
To be clear, you are talking about when I had my test light connected to B+ and I touched on the positive side of the light bulb circuit with the light bulb still plugged in and the light bulb wire disconnected from B+. Right?
VIheavyequipment
The short answer is this: If you are doing this test with a high ohm load in the circuit, the test light may not even light. If it is a low ohm load (like in the video) the test light lit brightly.
Another twist, if using an LED test light, it would even light with a high ohm load in the circuit as it doesn't require the same current flow to light the LED as it does an incandescent bulb.
This is one of the reasons I do not like the circuit testers with the red and green LEDs for power and ground ID.
In this application, one of those tools would have lit green on that positive side of the circuit telling you it is a ground, when it is not. It is an un-switched or turned off power supply.
There is so much to this. Hard to put all the variables into print.
First time I see a video of both you guys explaining the abc's. Awesome! Good clear and simple explanations. Surely a added value to all of us. Thumbs up. ;-)
ok i was watching scanners video on basic electrical review on his premium channel but this whole ground side switched and power side switched inputs and outputs i have to keep doing this till its second nature harder for some than others but i am power side switched and i am grounded so here i come in other words i understand it but i dont understand it which is frustrating its like im almost there but lack something hmmmm maybe knowledge
@Budget Boost DIY wow!!!!! Great find and tool to use!!!!!!!!!!!!!!!!!!!! Thank you very much for sharing it! :)
All u need is experience. Once you run into this issue hands on you’ll see things in a different way
This is what I took away to determine if it’s ground side switched or power side switches.
Put ground test lead (black wire ) on negative terminal of battery, next with the red test lead back probe the “light bulb” (circuit has to be off by the way) if you get a voltage on both wires then it’s ground side switched. If you get 0 voltage on both wires then it’s power side switched. Hope this made sense.
This will help me alot in the future,. I know some things about electricity but always scared to damage something in the car to find the source. thanks!
This is so important and should explain why you MUST disconnect an alternator COMPLETELY, not just the battery, before using arc welding on a vehicle.
Good Evening Ericthecarguy,ScannerDanner
Thanks 👍
From Nick Ayivor from London England UK 🇬🇧
Thanks to you and your guest for sharing your experience.
Thankyou I will have to watch this video a few times to understand properly, in college we have just been introduced to these concepts on paper .
I'm watching this video in 2024. Danner looks so young it's crazy
Great video! I really like these sort of videos, as I have a limited knowledge of electrical systems and really want to learn more. This was very easy to understand and had great info. You two are awesome as usual!
Excellent information! I have been wondering about the positive vs. negative side switching since I fixed my cars central locking remote system and read through some forum texts about central locking in general. Didn't quite understand how it works (got the remote control box installed anyway though), but this video really clears it up. Good work guys!
Great job keeping it simple. Easy to understand. Please create more video like this Eric and Paul.
Great video! The only thing I would've added to the demonstration is another short piece of wire with alligator clips on each end to more accurately simulate a switch. The benefit to this would be identifying a positive side switch with just the volt meter by reading the switch's terminals.
I think it also would've been nice to have a discussion about use cases for switching negative. But perhaps out of scope for this video.
When I was about 17 with my first car, negative side switching confussed the shit out of me until I drew a simple negative side switch diagram, then I got the light bulb moment. This should be a great smack in the face of logic for alot of people, great upload.
Muy buenos videos,uno aprende mucho con estos maestros,gracias Thank you
This is more important than most people realize...also, Scanner Danner sounds like a professional wrestler name.
Important info, especially with the advent of LED spotlights and light bars.
Im following these guys, They are MAGNIFICENT!
Hi Eric, just one thing that might be of interest, a 21 watt bulb on 12 volts draws approx. 2 amps, so by ohms law the filament of the bulb would be around , 6 ohms, now if you put an ohmmeter across that bulb it would read 0 ohms, try it, the only time the filament has 6 ohms is when it is red hot, if you could measure it then...other thing on mains electricity the switch is normally live side switched for safety reasons, so you don't get a shock from the bulb with it turned off....Fred in England.
Thanks for your input!
EricTheCarGuy By the way Eric and Paul, great video again, how far apart do you Guys live, does Paul drive or fly to yours Eric? Fred uk
Tom Smith
4.5 hour drive Tom. Not too bad.
g4vvq1983, it is true that resistance of an incandescent bulb rises as it heats up, but that bulb is not 0 ohms at room temperature. I think you need a more sensitive multimeter with sub-ohm range, that if you are at this stage of observation then the one you have is not versatile enough to help you proceed further in diagnostics. Many times you might have a bad electrical connection and it could help to see differences of an ohm, though another way through this issue is to measure the voltage drop across it (if you can power up the circuit).
13:38 instead of test lamp sir, you can use also multimeter by putting the one probe in positive terminal of battery and the other probe is for the wire you want to check.
You guys are too much am learning a lot of stuff from you. thank you so much
one thing you might ad when using a meter. Is where you set your meter. A lot of people don't know anything about the meter like me. And i never really sure where to set my meter since there all kinds of different setting on it. You know maybe show your meter and show where you have it set so people know for sure. I know its something we all should know but always been something that confused me ty mike
amazing video. thank you. This whole channel is a great learning tool.
Very good bite size info and fun to watch, more like this please.
the stumbling conversation is great!
haven't remained with much - it's important to know which one is which, and you use a light bulb to sort things out.
you could use "ghost voltage" when testing for control wire(unplugged) during the positive side switch as an alternative rather than a test light? as one would have ghost voltage and the other would have 0V if im not mistaken
I'd love a video like this on voltage drops; identifying and locating.
In electronics we call this sourcing (power side switching) and sinking (ground side switching). Its also good to understand most digital chips support more current when sinking.
good tip Kyle! never heard that before. why is that?
Similar in welding. Electrode positive or electrode negative usually translate into more or less heat. Well beside another "million" variables. :-)
Most digital chips don't handle enough current in automotive apps to matter, instead controlling mechanical or solid state relays, or a more integrated transistor switching which can be set up either way depending on the other requirements for the circuit.
Superb explanation. Great instructional prop. Very useful tutorial. Thank you.
Eric .... greetings from India.. very nice video and thoroughly informative.. definitely a coolest video
ground side switch used confused the hell out of me ...good explaination
Thanks for having this guy on, he's always great.
To have two of the brightest internet technicians coming from a little college like Rosedale is a real feather in their cap. I wouldn't hesitate to pump their tires.
Eric and Paul came from the same school? I did not know that. It's a small world after all.
Micscience
yea, we missed each other by one or two years. I was a 93 grad and I think he was 95?
spelunkerd That's what she said
MikeTheITGuy
haha nice!
Wonderful piece of knowledge and skills. Thanks a lot.
I need more to learning about short circuit.
Thanks about detail.
Pure gold, Eric and Paul!
Eric, I really love watching your videos. What I would like to see is more that are done with a town and country/grand caravan. Mine needs a new heater core (leaks) and I need some expert advice on actually doing the repair.
another easy way to confirm a ground sid is siply set voltmeter to ohms and test each side of the harness to ground this can also verifit if your looking at a poor connection as your resistance will be higher
Great video, while I did learn most of this stuff some 15+ years ago in school, I have forgotten most of it because I have not used it in so long. It's nice to have a good refresher once in a while. Eric, really can't wait for some Fairlane videos, I know you want to work with sponsors and what not for upgrades, parts etc. But I would think there must be some videos you could do on it right now, like simple maintenance stuff.
First, it's a Fairmont. Second, I've already shot the first video. Thanks for your interest.
Ah yes, Fairmont. I know the difference, just typed it wrong. My bad. I actually used to have a 86' Capri with the 5.0 HO and dual four barrels and edelbrock intake. It was a quick ride but a total rust bucket because it spent its life in New England with harsh winters. I ended up selling it from 2400 about 9 yearxs ago. I really regret iot now because I wish I had something to run at the track because I do not live far from Lebanon Valley drag strip. Anyways, cannot wait for some Fairmont videos. I'm not a Ford fanboy or anything (I like all makes, it's stupid not to) but I always loved the foxy body platform because of it's simplicity and the huge amount of parts and swapability. I mean hell, I could pout a F-150 dash in a mustang, heh. Keep em coming Eric.
You said that if you hook up your test light to positive side of the battery you just go ahead an touch the wires to find the ground side. Its true however your test light is not fused and it could fry the components on the negative side of the circuit.
GOOD things to know with a great show with knowledge.
Thanks Eric and Paul,
I look forward to the next electrical class. Good job!
Congratulations on turning over 400,000 subscribers!
so you know each other. Been watching the 2 of you individually. How did u 2 meet? Eric were u student at Rosedale? Was Paul your teacher? I consider both of you my personal teacher and it feels really good seeing both of you together. Now i'll just watch the vid. Congrats!
the best way to check for ground side switching is to check the switch. If you have power with the switch in the off position and nothing on both posts with the switch in the on position then you automatically know its ground switched because the load is burning the current
Thanks for the vid guys. Do you think we could see another video with you guys working on a car? Maybe out in the field perhaps. Thanks again..
Really helpful to understand how this all works
I have found some RAM trucks have a confusing combination of positive and negative switching. It can really complicate troubleshooting or installation of accessories.
Since electrons actually flow from the negative to the positive you can think of voltage as an electron vacuum. Another way to think of it would be as potential flow. The reason that you measure 0 volts on a power side switch is because the voltage between the battery ground and your other test lead is 0. There is no potential there. Whereas the voltage between the battery ground and the other test lead on a ground side switch would be 12 because there are 12 volts of difference, or potential, between the ground and positive on the battery.
This is awesome video. Thank you both. God bless.
Eric please post some more video on electric diagnosis
Best diagnostic video, EVER! Thank you.
I didn't know Jax from SOA teaches auto tech on the side. Sweet!
If you put the meter on continuity, the side that is open should be the switching side or control side. Just a thought!
Two great men in automotive
Thanks guys. I really enjoyed that vid. One question that is bugging me… When you were negative side switching and you tested the negative side of the circuit, why didn't the light come on? Isn't the circuit being completed by the voltmeter because its connected to the ground?
Technically you're right, the meter is completing the circuit which is how it measures the voltage. However the series resistance of the meter (which is just a fancy way of saying how much current will flow through it at a given voltage) is extremely high in the order of 10 megaohms or more which means at 12 volts less than a microamp of current will flow through the meter which isnt enough current to heat up the filament in the lightbulb. This incredibly small amount of current is enough for the meter to accurately measure voltage
@@oddball0045 I had this same question. Thank you for your explanation.
very well explained, cool to see paul in another vid
You guy's are awesome !! Keep up the good work. I just work on my own cars. Really good info. 👍
It's best to describe the grounding side as neg. side
So as not to confuse students that associate it to AC current power side neutral side
Since DC current flows neg to positive
No current flow= No voltage drop. Thats the biggest take away from this. Thank you!
Keep the guy that look at you like Eric looks Scan. ♡♡♡
Wow! guys I hope you fixed the issue with that light bulb. Seems to be a really important light bulb. Good luck!
One thumb up for Eric, one thumb up for Danny = 2 thumbs up =)
One thing I have learned about electric and that is you really need to practice with experiments to remember everything or you will just forget it all eventually.
Class is in session!! Shaddap and siddown!!
Hey Eric great vids. I just bought a 1947 plymouth with the original owners manual, It shows a positive ground system but the battery is hooked up as a negative system. Ir runs and all gauges work and horn but there are no lights anywhere. Is it due to the battery hook up or something else ?