The alternator has a two spade plug on the under side one is a direct hot from batteries the other side is what I was told is a exciter to open a rectifier. The back of alternator has three wires one a ground one goes to battery isolator and a small one that is red and goes in a wiring loom never to be traced out????
The original problem was the tac and voltmeter quit working and there was no wire to what I call the exciter side it did have the direct hot wire. Alternator has been tested and all is fine.