Engine off, key off, alternator makes a buzzing noise?

[Samckitt]

Anyone have any idea why?

[Lawrence]

The exciter wire which should be fed from ignition positive is being fed from battery positive and the regulator is on. That's what it was with mine anyway

[GBodyGMachine]

Yea, your alternator is not a a switched positive. Had the same problem.
Jeff

[Samckitt]

Which wire is the exciter wire? It is on a 95 LT1, hooked up through the factory 86 Monte wiring. Hmmm.
Thanks

[GBodyGMachine]

The one labeled Exciter?

You will have to get a wiring schematic.
J

[Samckitt]

The one labeled Exciter?

You will have to get a wiring schematic.
J

Oh yeah what was I thinking. I haven't looked at it yet, Im gonna go check it with a meter.

[MonzaRacer]

If its a CSI alt the big wire should go to battery positive(same as old SI series plug) and the f term should be key on, probably reversed.
If you still have issues give me a call at 812-709-1006. I did have my old CSI plug at home as I had a 140 amp CSI144 on my 70 MC.
Lee

[Samckitt]

OK shows how much my memory works. The alt only has 2 wires to it, one is connected to the post on the back & goes directly to the battery, & then there is only one in the connector, even though there is like 4 or 5 terminals on the alternator itself. Didn't hook it up to a meter, I'll do that tomorrow.

[Samckitt]

I had thought that it was wired wrong & power to it was not turned off when the key is off. So today I put a meter on it & found out that when the key is on there is around 12 volts going to the plug on the alternator (only one wire in it), when key is off there is about .8 volts going to it. This makes no since to me. Anyone have a clue?

[OHCbird]

Back-feed through an idiot light or gauge circuit?

[Coursey]

I have the same issue.

Did you figure out what is wrong?

I have heard possible bad diode or regulator.