voltage regulator

[MR12008]

I have a 2001 f250 7.3 PSD If Im reading my manual right it says the voltage regulator is internal to the alternator but auto zone has one listed for my year and model. So are they replacable? And how would i test it? Any body have a wiring diagram?

 

[BJS]

yes they are internal in that the black plastic stuff bolted to the back of the alternator is the regulator and you can remove and replace it.

Here is a good link on testing alternators