225 charging problem

Learn to test ON THE CAR, so you can also test the harness, etc.

Old systems (pre 70) have one field lead (green) to the alternator from the VR. It sends varying amounts of power to the field to control output.

In order to simply and quickly test the alternator AND the output charging circuit, simply disconnect the green field wire, either at the VR or the alternator, and jumper 12V to it from the battery. Slowly rev up the engine, watching the ammeter. It should start to charge, then more, and go to max. If you monitor the battery V, and you should, try not to let it go above 16V

For a quick idea of "if" the alternator is outputting enough current, with the engine reved some, turn on lights, heater, etc, push on brake. It should be able to keep up unless the battery is really dead. That is, the ammeter should remain on the "charge" side.

VR MUST be grounded. MUST