CHECK your wiring
We pretty much checked the output wiring in the above test. If the alternator charges in the above test, now test the field wiring. One of the field wires to the alternator should come from "ignition run" from the key. Hook your voltmeter to one or other wires, turn the key to "run." Should be "same as battery."
The other wire only goes one place....to the VR. Unhook the VR, turn the key to off, unhook the second alternator field wire. Check with a voltmeter that there is NO voltage on this wire. Now switch the meter to resistance (ohms) With the meter hooked to BOTH ends of this wire, there should be continuity---very low resistance
The remaining VR connection should have battery voltage on it with the key in "run."
The VR MUST be grounded to work
IF THE alternator charged in the earlier test, hook all wiring back up "normal." What you want to do now is eliminate the VR, and check the field wiring. Unhook the VR and devise a way to jumper across the two VR connections at that connector. A couple of small machine screws, etc.
Now go to the alternator and disconnect the wire coming from the key. This is the wire you checked earlier that has battery voltage on, with the key in "run." Rig a jumper from that disconnected alternator field terminal (the alternator not the wire) and ground it. Again run the engine, and the thing should rise in voltage and show a charge. If this is the case AND YOU ARE SURE the VR was properly grounded, replace the VR
