charging system not working

[Markviiiedrea]

My friends 93 mark died the other night and we found out that the alternator took a dump and fortunately it was still under warranty from Napa. so we got a new one and installed it, but the battery light is still on and the system still is not charging.

When we first installed it the system was charging at 12.81 V but fell off shortly after

So I thought it might need a new bat and I took the old one out and had it tested and it was fine.

Took the car for a test drive and for a moment the light went off but came back on again, checked all the wiring and every thing looks tight. For kicks and giggles we checked for codes but nothing came up and nothing on the message center.

WTF?
so now what? any idea's?

 

[Phantom&RedGoat2004]

There are parts places around that can test the alt while it's still on the car, but it may just be a cooked wire somewhere.

 

[Lugnut]

My friends 93 mark died the other night and we found out that the alternator took a dump and fortunately it was still under warranty from Napa. so we got a new one and installed it, but the battery light is still on and the system still is not charging.

When we first installed it the system was charging at 12.81 V but fell off shortly after

So I thought it might need a new bat and I took the old one out and had it tested and it was fine.

Took the car for a test drive and for a moment the light went off but came back on again, checked all the wiring and every thing looks tight. For kicks and giggles we checked for codes but nothing came up and nothing on the message center.

WTF?
so now what? any idea's?

12.81 is not just exactly more than marginal for what an alternator should be putting out. Not too sure you didn't get a rebuilt alternator that was more or less DOA, happens all the time with rebuilt alternators and starters. But it could be a case of a bad ground cable or a ground cable connection that has corroded at the block and/or chassis. You might also want to check the resistance on the positive cable.

Good Luck!

 

[chicken]

it should be around 14.2~ish not no 12 nothing! check for power on the big wire at the alt and some of the small wires, 93 is too old for me to run it throught the ford tech site, sounds like the alt isnt getting any power