1997 Ford mustang V6 alternator wont hold charge and crank and no start

[yaboity]

Hey everyone i have a 1997 Ford mustang v6 that has not been holding charge i do not get a battery light and i do not get a theft light, for a little bit i was able to unbolt the gauge cluster and sit it flat to get the battery light to come on before start well now its not coming on at all how do i fix this is this a PCM problem or do i have to get my dash harness rewired i need help this is insane of a problem and im about to have to abandon this car for it

 

[Noobz347]

I actually think that it's an alternator problem. Every alternator has a diode in it that allows power to travel in only one direction. If the diode fails then the battery tries to "motor" the alternator when it's not spinning.

If you know your battery is good but the car is draining anyway, this is likely the culprit. You can disconnect the charge wire from the alternator and leave it overnight to confirm.

 

[yaboity]

Ive gotten 3 different alternators and have had them bench tested before this mess i should have mentioned that

 

[Noobz347]

That doesn't completely rule out the problem, however, you still have what sounds like a pretty significant power draw somewhere.

How old is the battery?

Here's a video about performing a parasitic draw test:

View: https://www.youtube.com/watch?v=xBVmbYBxMyo

 

[Noobz347]

If you're still getting a significant draw with the alternator feed wire disconnected then you can start pulling fuses until the draw drops significantly. That'll be your problem child.

 

[yaboity]

I have a new battery new alternator as stated above but thank you all im selling the car ive never seen this kind of problem