Voltage regulator output numbers

[Dodonne2]

Does anyone know the numbers for voltage coming out of each terminal from the voltage regulator. Should they all be the same voltage coming off the battery?. My yellow cable matches the battery voltage. My white cables that attached to the alternator only have 7 volts. The black cable which wires into the orange and blue connected to the alternator has 12.8 volts. I assume 7 volts out of the white wires is not good?

 

[Dodonne2]

Also when I turn the fan for the heat on my voltage drops from 14.1 to 13.7? This can't be normal right?

 

[franklin2]

White wire is the stator wire, 7 volts on the stator is normal. The yellow wire is the feedback to the voltage regulator, so it should have system voltage on it, which will be battery voltage. The orange and blue wire is the field wire. It will have anything from a couple of volts to battery voltage. If it has battery voltage that will throw the alternator wide open. This wire is not wired to anything but the F terminal on the alternator, and the field terminal on the regulator.

The black cable you are talking about, does it have a orange stripe on it and is larger than the other wires? If so, this is your output wire and is wired to the 12v wiring which feeds the trucks electrical and feeds the battery + also.

 

[franklin2]

Also when I turn the fan for the heat on my voltage drops from 14.1 to 13.7? This can't be normal right?

Perfectly normal, especially at idle. The output of the alternator is lower at idle. If you rev the engine it should come up a little bit, but still may be a little low if you have your meter on the cab wiring. The factory saved every dime they could and the wiring is just big enough to do the job. So you will get some voltage drop inside the cab.

 

[Dodonne2]

Thanks everyone!