Alternator Charging Problem/Fusable link

[revhead347]

I still haven't gotten my alternator to charge even though I put a new pigtail on it. I removed the pigtail and stuck a volt gauge in there. There is no power going to the yellow wire when the car is running, so that's probably the problem. I'm also not getting a bad charge indication in the car. The wiring diagram shows a fusable link in the circuit. Anyone know where that fusable link is? The 10A fuse in the fuse box is good, and has good voltage on both sides of it.

Kurt

 

[64post]

Sounds like the field wire is not powering up. 1st thing:Check the B+ (big red or BK/O wire on 6mm post) for steady battery voltage with key on and off, check the field wire (w/key on and running) the black and white in it's own con.) check the bulb in the cluster, , should light up with key on engine off, some vehicles will not charge without a good indicator bulb (the red battery pic must light up). You'll need a 12v test light or DVOM, Back probe 20 amp fuse in e/compt/junction box, with fuse in probe the backsides of the fuse, both must light up your test light, good luck The link should be in the big B+ wire loom near the junction box.

 

[Adam95GT]

Its over under the fuse box i think...

 

[HISSIN50]

They're often where the cable goes down the side of the PS pump.

Other tidbits:

There's a resistor in the excite circuit in case the battery light burns out.

The alt fuse (as noted above) should be a 20 amper as I recall, not a 10.

What yellow wire are you looking at? Do you mean the lt green/red wire?

On the regulator, if A has battery voltage and I has nominal voltage, S should float about 1/2 battery voltage while the car is idling (assuming the charge cable to have complete continuity).

Two areas that can be problematic are the charge distribution junction (on the side of the fusebox). Be sure the connection is tight and clean. And the alt fuse (that you checked) can get corroded or have a loose connection with the fuse's blades. This can lead to intermittent situations where the alt thinks the charge cable is open.

 

[revhead347]

Thanks for all the info guys. Off to work, so I'll have to read some of it later.

Kurt

 

[revhead347]

Ok. Had a hell of a time the last two days at work and I'm exhausted. I had assumed the yellow wire was the power wire to the alternator. I know the white wire is the field wire. Why that isn't run internally is beyond me. The green wire with the red stripe seemed to be the one for the dash indication, which is definately not working. I guess that bulb has burned out. I don't get home from work for another 2 days, so I'll mess with some of those things if it isn't too cold. Good chance the junction down by the fuse box is full of crap.

Kurt

 

[revhead347]

Alright, I thought I had it, and then not so much. Obviously since I had a problem, I started with what I knew was wrong. I took out the instrument cluster and swapped the bulbs, which didn't fix it. Taking out the instrument cluster in my car is no small project. I have to remove the tach, and I also have two mechanical guages mounted to the instrument cluster bezel. I found that the circuit was fried where the right instrument cluster harness hooks up.

No biggie, I have a spare, so I pieced together a new instrument cluster, and quickly hooked it up at that location. Turned the key to the on position, and the light works. Started the car, and the alternator was charging. I gave myself a pat on the back, and proceeded to put the instrument cluster bezel back on, remount the tack, and remount the bezel with the guages. Being happy to have it working again, I started the car to watch it in action again, and maybe revel in being able to get this car off to the alignment shop soon. I started the car, there was a quick puff of smoke from behind the instrument cluster, and the alternator was dead again.

What's your thoughts?

Kurt