Charging Circuit Woes

The clearances between the back of the alternator studs and the cylinder head are very close. In fact I think that there is a Pantera specific alternator because this is such a common occurance.

Get in there with a mirror and make sure that you aren't grounding the alternator terminal studs at the head.

If it's ok, start the car and put a voltmeter on the battery terminals of the car running and make sure of the voltage the battery is recieving.

Check the big chassis grounds under the trunk, etc.

Make an offering to Voltare, the god of the Pantera electrical system.

Something will give.

I had an alternator one time that appeared to work fine. Show charging on the amp meeter, no light. But after driving around for a while at night the car would not start. Turned out to be an internal short in the rotor.

My mothers town car ran fine and did not have a gen light, but once shut off for several hours, the battery was totally dead. A diode was shorted.

So yes, it is possible for the system to look fine but not be.

Took the alternator to have it tested today and yes despite it's 'newness' it has a diode or something gone internally. It is now being rebuilt.

Thanks for all the help.
Julian

The continuing saga.....

Rebuilt alternator fitted to car, start the car yes we have current Houston... gauge at max (75A). Drive to work today and it shows constant 60A (100A alternator), so call my alternator repairer, take car over they test circuit and say it has a bad diode. I have to give it to them though I had great customer service all five guys had to come out and see what was going on.

Because they can't access the alternator I gotta take the front cover off and remove it again over the weekend. But my worry is what would cause the diode to go out in such a short time? I'm worried now that something else may be causing this, is that common? Thy will replace the diode this time, but I don't want to put it back on just to be in the same place again next week. Any input or thoughts?

Julian