Nice one Chad! I've seen this same problem twice, both in Ford Edge's. You are definitely correct about installing OEM alternators also. First time, customer requested aftermarket, same over-voltage problem. After that I would never install aftermarket alternator on a computer controlled Ford again. Thanks for your thorough explanation and direction. Great job man.
I’ve been burned too many times with aftermarket alternators on certain vehicles. I complained to rotating electrical rep one time and he told that the most alternators that are sent back defective aren’t actually defective but many of them just have the incorrect regulator installed. I told him that still means it’s defective and I’ll be filing a labor claim.
Hello Chad, I know that adding the red arrows to your edit isn’t a major thing but it’s actually a huge plus for those viewing the video. An excellent diag as always. Thank you for sharing your knowledge with us.
Sometimes I forget that others can see what data pid I’m looking at or are unfamiliar with the tool I’m using so I hope the arrows and highlighted boxes will help. Thanks for the confirmation and sharing feedback. It helps me with future video edits.
Thank you very much for the explanation of the put up and pull down on how it works I bought a mic sig scope and it has a ford smart alternator test but the way you explained the system I now know what to look for thanks again and god bless you SIR
I too am dealing with same issues with my 2012 F-150. Replaced alternator with Motorcraft 225-amp (over $600), and replaced Motorcraft AGM battery with a Motorcraft lead-acid (over $250) keeping both old alternator and battery yet charging issues persist. I've now purchased a replacement factory OEM charging wire harness (battery, alternator, a/c, starter) and just waiting for a warm weekend when I can do the swap. Not sure how many hours it will take to remove old harness but guessing it will be several. Once out I can inspect for damage and location of same (corrosion, mice, chipmunks, squirrels chewing on insulation) and prepare new harness so this can never happen again in future. I have a Banks digital monitor mounted to driver pillar and most of time vehicle charges normally at 14.3 vdc, then for no reason it dumps down to 12.8 vdc while at speed which then fluctuates (11.9 - 15 vdc) up/down with the throttle pedal position (higher voltage pedal up / lower voltage pedal down) alternator makes whirling sound (pedal up) in addition, headlights, dash lights briefly dim when launching from a stop. I do not understand the connection between the throttle pedal and the charging system but somehow they are both connected. As this has occurred with both alternators/batteries, I do believe wire harness is to fault.
I have a 18 Mustang GT and the alternator gauge bounces between 12.0 and 13.5V. I am wondering if this a common state for the car (when the PCM is calling for more power)? it seems to go up when I take my foot off the gas and start to slow either by applying the brake peddle or just coasting down a hill. Any direction would be great.
Chad, are you in the habit of only boosting a stranger with the donor engine off? I learned old school, to leave donor engine on so voltage is higher, better energy transfer, and no risk of depleting the donor battery. However new cars don't like to be boosted above 12 V, there's a risk of throwing codes on the vehicle with the dead battery. What do you think?
I prefer to use a jump box like the jumpncarry 660 or noco jump box but I will jump start with most of my vehicles if needed. I will not jump start with my highlander hybrid. It’s not worth the risk of damaging the dc/dc converter. I think it would be safest to turn both cars off while connecting the cables and then start the car with a good battery and let it run for a while to jump the other car. Perhaps shut off good car before cranking the dead car to prevent the 300-500 amp load from damaging the alternator. I honestly hadn’t given it much thought before since my vehicle are all over 10yrs old. New finicky electronics may make carrying a booster pack a more common item.
Brother I'm having the same issue after I left my car sitting for 11 days to get inspection. I picked it up and this light came on. Now I'm being quoted $750 for an alternator. But the battery in this car is over 5 years old. Could it just be the battery?
Just quick question does the alternator put out a diagnostic bias voltage on the monitor wire like the pcm does on the control wire , just subscribed was looking for info and testing ford smart charge and found your great channel i didnt know about , thanks again .
The alternator outputs the bias on the command wire and the pcm toggles to ground. The pcm supplies bias to monitor wire and alternator toggles to ground.
@@ThePracticalMechanic Thanks for reply , reason i asked is i noticed a 2/3 volt on the command wire when the alt was unplugged and the pcm was toggling it , cheers again.
@@clueless6559 ah. I think your correct. That bias is probably for an open circuit test. If the pcm sees 3 volts it may set an open circuit code. If it sees 12 volts it will set short to b+ and stuck to ground it sets short to ground code. I misunderstood on the original question.
i had to rewire my genmon wire from alternator 3 wire connector to pcm harness.. on my 2011 f150. its good to go now edit had to pay for a month of alldata.. to get the diagrams for the rewire.
Greetings , great info and notes 👌 For DIY , if we don't have scope , how can we test the alternator charging , with the multimeter , and know for sure is the alternator at fault ? What do we test ?
You could use a combination of the voltage setting and duty cycle setting to figure out what the signals are doing. I just like the easy visual that the scope gives.
hey brother plz reply back , i am having ford fiesta diesel , whenever i start the car battery warning light comes on the dash but if i revv the car till 4k rpm it disappears , and wont come back till i turn off the car , what is the issue
@@evanstephayn272 depends on if the vehicle is charging properly. If you check the charging voltage and it’s normal, then you could probably drive it that way for a long period of time. If the alternator is under charging or overcharging, you risk damaging other components.
@@ThePracticalMechanic I did recieve the check charging system light for a short period of time, I was able to check my voltage which is at about 14.5, However, I did not have the reader plugged in while, The car had the code, (the reader plugs into my cigarette lighter spot), I had a faulty alternator on my other honda CRV which successfully showed the jumping in voltages. Woul;d it be worth monitoring the voltage while continuing to drive It or would It be worth replacing it ASAP, I do believe that it is still charging, and have seen no other signs of a bad alternator, ( dimming/ flickering lights, trouble starting, etc)
I just foxed a dodge pickup with same set up for alternator it had been to another shop thry replaced both batteries (diesel) the alternator no fix they told customer needs PCM he declined i found the wires at the plug at alternator broken new pigtail and connector unit charges
Nice one Chad! I've seen this same problem twice, both in Ford Edge's.
You are definitely correct about installing OEM alternators also. First time, customer requested aftermarket, same over-voltage problem. After that I would never install aftermarket alternator on a computer controlled Ford again.
Thanks for your thorough explanation and direction. Great job man.
I’ve been burned too many times with aftermarket alternators on certain vehicles. I complained to rotating electrical rep one time and he told that the most alternators that are sent back defective aren’t actually defective but many of them just have the incorrect regulator installed. I told him that still means it’s defective and I’ll be filing a labor claim.
Hello Chad,
I know that adding the red arrows to your edit isn’t a major thing but it’s actually a huge plus for those viewing the video. An excellent diag as always. Thank you for sharing your knowledge with us.
Sometimes I forget that others can see what data pid I’m looking at or are unfamiliar with the tool I’m using so I hope the arrows and highlighted boxes will help. Thanks for the confirmation and sharing feedback. It helps me with future video edits.
Thank you for your video's. That was a good explanation for testing "F" circuit codes. I hope you and your family have a Happy, Healthy New Year.
Thank you. I hope you and yours have a safe and happy new years as well.
Thank you very much for the explanation of the put up and pull down on how it works I bought a mic sig scope and it has a ford smart alternator test but the way you explained the system I now know what to look for thanks again and god bless you SIR
Great Job Chad. I hope the new year treats you guys good! Keep the content rolling. I can’t get enough!
So far so good but we are only a few days in😬. Hope you and the family have a great year as well.
Great video and informative, thank you for this
I too am dealing with same issues with my 2012 F-150. Replaced alternator with Motorcraft 225-amp (over $600), and replaced Motorcraft AGM battery with a Motorcraft lead-acid (over $250) keeping both old alternator and battery yet charging issues persist. I've now purchased a replacement factory OEM charging wire harness (battery, alternator, a/c, starter) and just waiting for a warm weekend when I can do the swap. Not sure how many hours it will take to remove old harness but guessing it will be several. Once out I can inspect for damage and location of same (corrosion, mice, chipmunks, squirrels chewing on insulation) and prepare new harness so this can never happen again in future. I have a Banks digital monitor mounted to driver pillar and most of time vehicle charges normally at 14.3 vdc, then for no reason it dumps down to 12.8 vdc while at speed which then fluctuates (11.9 - 15 vdc) up/down with the throttle pedal position (higher voltage pedal up / lower voltage pedal down) alternator makes whirling sound (pedal up) in addition, headlights, dash lights briefly dim when launching from a stop. I do not understand the connection between the throttle pedal and the charging system but somehow they are both connected. As this has occurred with both alternators/batteries, I do believe wire harness is to fault.
excellent video Great job
Getting same message about 10 minutes after installed new battery. Will it go away in 4-8 hours. Is it ok to drive car?
I have a 18 Mustang GT and the alternator gauge bounces between 12.0 and 13.5V. I am wondering if this a common state for the car (when the PCM is calling for more power)? it seems to go up when I take my foot off the gas and start to slow either by applying the brake peddle or just coasting down a hill. Any direction would be great.
PRODIGY THE PRACTICAL MECHANIC
THANK YOU FOR SHARING YOUR KNOWLEDGE WITH US
PRODIGY THE PRACTICAL MECHANIC
From Nick Ayivor from London England UK 🇬🇧
Chad, are you in the habit of only boosting a stranger with the donor engine off? I learned old school, to leave donor engine on so voltage is higher, better energy transfer, and no risk of depleting the donor battery. However new cars don't like to be boosted above 12 V, there's a risk of throwing codes on the vehicle with the dead battery. What do you think?
I prefer to use a jump box like the jumpncarry 660 or noco jump box but I will jump start with most of my vehicles if needed. I will not jump start with my highlander hybrid. It’s not worth the risk of damaging the dc/dc converter.
I think it would be safest to turn both cars off while connecting the cables and then start the car with a good battery and let it run for a while to jump the other car. Perhaps shut off good car before cranking the dead car to prevent the 300-500 amp load from damaging the alternator.
I honestly hadn’t given it much thought before since my vehicle are all over 10yrs old. New finicky electronics may make carrying a booster pack a more common item.
Hi, nothing happens when you disconnect the alternator socket for testing? does it affect anything? thanks
Brother I'm having the same issue after I left my car sitting for 11 days to get inspection. I picked it up and this light came on. Now I'm being quoted $750 for an alternator. But the battery in this car is over 5 years old. Could it just be the battery?
Take your battery to get checked, change it if need to. However, if the charge system appears very likely that your alternator also was dying as well
Good call
Just quick question does the alternator put out a diagnostic bias voltage on the monitor wire like the pcm does on the control wire , just subscribed was looking for info and testing ford smart charge and found your great channel i didnt know about , thanks again .
The alternator outputs the bias on the command wire and the pcm toggles to ground. The pcm supplies bias to monitor wire and alternator toggles to ground.
@@ThePracticalMechanic Thanks for reply , reason i asked is i noticed a 2/3 volt on the command wire when the alt was unplugged and the pcm was toggling it , cheers again.
@@clueless6559 ah. I think your correct. That bias is probably for an open circuit test. If the pcm sees 3 volts it may set an open circuit code. If it sees 12 volts it will set short to b+ and stuck to ground it sets short to ground code. I misunderstood on the original question.
i had to rewire my genmon wire from alternator 3 wire connector to pcm harness.. on my 2011 f150. its good to go now
edit had to pay for a month of alldata.. to get the diagrams for the rewire.
Greetings , great info and notes 👌
For DIY , if we don't have scope , how can we test the alternator charging , with the multimeter , and know for sure is the alternator at fault ?
What do we test ?
Can this be seen with a voltmeter and not just a scope?
You could use a combination of the voltage setting and duty cycle setting to figure out what the signals are doing. I just like the easy visual that the scope gives.
Grasias
hey brother plz reply back , i am having ford fiesta diesel , whenever i start the car battery warning light comes on the dash but if i revv the car till 4k rpm it disappears , and wont come back till i turn off the car , what is the issue
How long can a car run with a faulty regulator??
@@evanstephayn272 depends on if the vehicle is charging properly. If you check the charging voltage and it’s normal, then you could probably drive it that way for a long period of time. If the alternator is under charging or overcharging, you risk damaging other components.
@@ThePracticalMechanic I did recieve the check charging system light for a short period of time, I was able to check my voltage which is at about 14.5, However, I did not have the reader plugged in while, The car had the code, (the reader plugs into my cigarette lighter spot), I had a faulty alternator on my other honda CRV which successfully showed the jumping in voltages. Woul;d it be worth monitoring the voltage while continuing to drive It or would It be worth replacing it ASAP, I do believe that it is still charging, and have seen no other signs of a bad alternator, ( dimming/ flickering lights, trouble starting, etc)
What scanner do you use
This was the Snapon Zeus
thnks
I just foxed a dodge pickup with same set up for alternator it had been to another shop thry replaced both batteries (diesel) the alternator no fix they told customer needs PCM he declined i found the wires at the plug at alternator broken new pigtail and connector unit charges
All it takes is a little testing and you can normally isolate the true fault. Good work.
Eco BOOM 1.5L a couple hours diag time exceeds the cars value.
Quality is JoB NONE! Have you driven a Ford lately!