Alternator does not charge

:banghead: I have a 1997 Isuzu Rodeo Manual Transmission, 3.2L V6. The alternator went out and evidently took the ECU with it. Both have been replaced, but the alternator is still not charging. The mechanic is stumped. Any ideas?

:banghead: I have a 1997 Isuzu Rodeo Manual Transmission, 3.2L V6. The alternator went out and evidently took the ECU with it. Both have been replaced, but the alternator is still not charging. The mechanic is stumped. Any ideas?Does it not charge at all or does it only stop charging when you accelerate?

check all the grounds...

you may not have a complete circuit, not enough to let the battery charge-- but for the truck to start (unless you're having issues with that also)

Just because its a new alternator doesn't mean it works. Probably got a bad one. If the mechanic is stumped already, he must not be a very good one.

Stumped mechanics go for the "the ECU must be bad" every time!

I'm currently working on a forklift at work which appears to have oil in the antifreeze. I've had several other mechanics tell me its a blown head gasket. I've stopped believing what other people say and I check things out for myself. I was surprised to see no sign of coolant contamination in the engine oil. Then I noticed the transmission cooler lines going to the radiator. Checked the transmission fluid, yep, all milky looking and smelling of antifreeze. Not a blown head gasket but leaky trans cooler lines inside the radiator.

Your mechanic probably is nothing more than a parts changer. He only knows what other people tell him and can't diagnose much on his own. Get another mechanic. It's pretty easy to tell if an alternator is bad.

It could very well be that the new alternator is bad but then again it could be that his vehicle is acting completely normal and not charging when the engine is under load... as it is supposed to. So we could speculate all day long as to what the problem is but with out any additional input from rodeo1997 it's pretty much a useless endevour. :)