Charging system problem

sounds like a bad rebuild. the only other thing is if you have the wires mixed up some how.

 

I think u have a bad rebuild. If u started w/o the alt. on the car and no whine I wud return the alt. to the rebuilder.

 

Im thinkin bad build also. Would a bad bearing in the alternator cause low voltage thus making the alt light come on. I kinda think they didnt replace the bearings.

 

The thing that puzzles me is if I unhook the voltage regulator harness it stops the whining. I did this before and after the rebuild. I have triple checked the wires on the back of the alternator. Could the wires from the volt reg to alt be bad?

 

If u think the wires are bad, u cud test them for continuity and resistance after disconnecting them frm their sources. I don't know what resistance values are but they shud be vry,vry low to none. It goes w/o saying, "no continuity" replace the wire/harness.

 

What do I need to check the continuity and resistance?

 

You can use the same meter you measured the voltages with. Honestly, at this point, I'm going to go with the others who suggested bad alternator rebuild. If the whine stops when you unplug the regulator, you are disconnecting the field circuit, therefore no current gets produced. I'll guess somewhere in the stator the winding got shorted out. I'd take it back and get another alternator.
I'll also bet you have your voltage gauge switched through your ignition. That will cause the voltage drop, as the ignition is activated and drawing current even though the engine is off.

 

Alt is getting rebuilt again today. Hope they get it right the second time around.

 

Got the alternator back for the second time Now. I hooked it up to find out I still have the same problem.

 

I assume you are running the factory alternator and regulator setup?
If you have not done so, double check your wiring here: http://1bad6t.com/Maverick/repair/engine_repair_02.html

 

I have checked all the wires and they seem good.

 

Make sure the engine ground and voltage regulator ground (screw) are in good condition.

If your Alt light stays on with the engine running, that means your field relay may not be closing.
With the engine running, check the S terminal of the voltage regulator for 12V+.
With the engine running, check the F terminal of the voltage regulator for voltage greater than 0V.
With the engine NOT running, check the A terminal of the voltage regulator for 12V+.

 

How would I check them? Im not sure I follow.

 

Ok, no prob.
Do you have a multimeter (voltmeter)? Or do you have a 12V test light?

 

I have one. Are you saying to test the back of the alternator?