1985 4runner alternator issues

[devlsh1]

I have gone through 3 alternators in 2 years since i did my motor rebuild. They last about 6 months or so and then just stop charging (yes they are remans from Autozone). As soon as I replace it everything is great, am I getting bad alternators or do I have another issue...ground etc??? its the ground that comes off the top of the alternator correct? does anything else connect to that ground or can I run a new one straight to frame or battery ground? Any help would be great.
Thanks

 

[KLF]

This might be due to continuous high charging demand on the alternator. How's your battery? Connections good?

There is a black (I think) wire in the alternator harness with a large ring terminal on it, that is the ground connection. It's supposed to be on one of the engine mount bolts, doesn't really matter which one. The other wire with the ring terminal (thicker white one) is the charge wire, it goes to the stud on the back of the alternator.

Might check your other grounds, especially the one that comes off the - terminal of the battery and goes to the inner fender then down to the engine. There's another one at the back of the engine, to the firewall, and one on the intake in the engine harness.

Are you running a large load, like a big honkin' stereo or something?

 

[pappy]

I think the ground KLF is talking about bolts up to the power steering pump. I would make sure the fat white wire is tight on the stud to the alternator. That wire feeds up to the fuse block on the passenger side of the engine bay, runs through the 80A fusable link, then to the battery and fuse block. Make sure the connections are tight.

Also make sure the connector on the back of the alternator is plugged in tight. It has a wire that serves as the excite for the alternator.

 

[TCinVA]

Maybe check for a ground that goes from the engine block to the frame on the passenger side, but it could just be a crappy alternator.

 

[ajordan1975]

I'm going w/ the AZ alt. I worked at one many years ago and that was a very common prob. I never buy starters or alt from them.