1964 Plymouth Valiant Power Issue

OK here is what...............the single field connector is used up through 69 UNLESS the car has been modified. To see if the alternator is capable of charging, clip your voltmeter to the big stud on the back of the alternator. Start and run the engine and slowly bring up RPM. The voltmeter should rise above 12 on up to about 14 or a little more.

If it is way way high, this indicates the charge output wire is not continous to the battery....such as a bad connection in the bulkhead connector or ammeter

If it stays low, down around 12 or less, it is not charging

If not..........now disconnect the green wire either at the VR or alternator. If you disconnect at the VR, the following test will verify that wire integrity. Connect the wire end to a jumper wire to the battery. You should see a small spark in subdued lighting when you connect/ disconnect the wire. With your jumper connected, again run the engine and bring up RPM. Again monitor voltage, either at the alternator stud or at the battery. Voltage should rise above 12V don't allow it past 15-16

If this happens, the alternator is OK. If the voltage stays low, either investigate new brushes/ bearings or be prepared to dig into the alternator, or replace it

Next, verify you have 12V getting TO the VR. Turn the key to run, engine off. Measure voltage at the VR "ign" terminal. Should be "same as battery"

If this happens, and the alternator was charging in the first test, replace the VR