Alternator issues

[stephen]

From the "I learned it the hard way" file.

* Alternators are WAY better than generators, particularly if you run AC and lights.
* Go ahead and buy the bracket parts and pulley from a supplier, but get the alternator from Advance Auto or somewhere. The suppliers want $80 for a $22 alternator.
*Put washers under the bracket between it and the block. This way, the bolt on the adjusting bracket goes in to the alternator from the FRONT. Otherwise, it goes from the rear and is a PITA.

MOST IMPORTANTLY
These conversions are designed around a late '70's to mid '80's GM alternator. This has a drawback...It requires "feedback" (incorrect, technically, but just to keep it simple) from a 12V source on the white wire in order to activate the alternator. The idiot light is in this circuit. IF THE IDIOT LIGHT BURNS OUT, THE ALTERNATOR WILL NOT CHARGE.

This won't show up on the typical portable testing equipment. It simply says "bad alternator". Three warranty alternators later, I figured it out. BUT they obviously didn't warranty the labor or the headache.

Have a good one.

[nomadbird]

Thanks for sharing the alternator experience. This is probably the first upgrade a person would want to make when modernizing an old car. Now you have the oomph to run the AC and electric radiator fan.

The question I have is this: Doesn't the GEN light come on when the key is in the "run" position with the engine not running? It seems like it should.

Tom