Alternator or something else?

[janders211]

My car has not been charging. I connected 12v(from the fuel pump relay) to the top wire of the Alternator 2 wire plug (the exciter, or on switch, or whatever it is called). I got 13.5-14v (vs. 12v at idle, and 12.5v revving at 2k).
That lasted about 5 min, and I'm at 11.5v now.

Also, with the car off if I connect 12v to that top wire the alternator sort of growls (sometimes it does, sometimes it did not).


Mehhh...probably need a new alternator..exact same crap happened 6 months ago.

[Chrischeezer]

why would you test from the fuel pump relay? ... why not the 12v direct power and ground..??

[dOMEmE]

why would you test from the fuel pump relay? ... why not the 12v direct power and ground..??

why not both.....

[Vision Garage]

if you are changing alternators every 6 months you might wan to check your wiring anyway. Make sure all the grounds are good. I had the problem a while back and after getting a new alternator, it still wouldnt charge. Found it to be the ground leading to the fusebox.

[janders211]

why would you test from the fuel pump relay? ... why not the 12v direct power and ground..??

I tested from both the battery directly, and from the relay... (it also triggers my efans).

I wired it to the relay so the alternator isn't sucking power with the car off.

I'll try regrounding it fo' giggity

**Edit**extra ground worked for 5 min?
I think the alternator may be working cold, and then craps out warm
**re-edit**

I took apart the alternator, cleaned it-sanded all the leads ...and it kind of works. The battery will stay at 12.0(idle) and 12.9(2k RPM).....unless I turn the lights on.

[janders211]

Replaced the alternator- all problems gone