Load Testing Alternator On Vehicle

makuloco2000 · January 1, 2014

I made a brief video on the procedure I have used for many years here at the dealer that has not failed me yet in identifying a weak but functioning alternator causing many headaches like no starts after changing the battery and only checking the voltage output of the Alt. I hope this helps as there really isn't a need to take the alt off to get it tested. No fancy tools required.

ponkotsu · January 1, 2014

Thanks for sharing. I think way too many alternators get replaced unnecessarily. How you showed is what I've always done also. If you have a bad alternator it's usually pretty obvious. Another thing I check is the AC ripple. Switch the meter to AC and the AC should be close to zero. If the diodes are bad you could be getting some noise that might create some random computer problems.

makuloco2000 · January 1, 2014

ponkotsu said:
Thanks for sharing. I think way too many alternators get replaced unnecessarily. How you showed is what I've always done also. If you have a bad alternator it's usually pretty obvious. Another thing I check is the AC ripple. Switch the meter to AC and the AC should be close to zero. If the diodes are bad you could be getting some noise that might create some random computer problems.

Yep there is that too, great tip!

Markaprice73 · January 3, 2014

Good tip. Thanks for sharing. I always turn on everything when checking

also wipers, high beams, hazards, radio, dome lights, etc. I try to imagine my Wife sitting on the side of a dark road at night in the cold rain waiting for me to come fix a flat

Keep those Explorer videos coming!!! Ive watched all you youtube vids. Thanks

makuloco2000 · January 3, 2014

Wow thanks for watching. I will make more as they come in to the shop.

stahrman · January 3, 2014

makuloco2000 said:
Wow thanks for watching. I will make more as they come in to the shop.

Awesome.....very much appreciated!! :salute:

Donystoy · January 4, 2014

Good video!
I remember the old days before all the computer crap been able to test the alternator by turning on the headlights and disconnecting the battery. If the engine kept running, the alternator was fine. How times have changed.

makuloco2000 · January 6, 2014

Yep those were the days

Load Testing Alternator On Vehicle

makuloco2000

Well-Known Member

ponkotsu

Well-Known Member

makuloco2000

Well-Known Member

Markaprice73

Well-Known Member

makuloco2000

Well-Known Member

stahrman

Member

Donystoy

Well-Known Member

makuloco2000

Well-Known Member

Featured images

Featured images

Similar Threads