65 Dart Alternator Not Charging

HOW THESE WORK

Simply. Without getting into circuit complications, the output circuit of the alternator is the big stud and the case which is ground. That is ALWAYS hooked DIRECTLY to the battery (through the ammeter

FIELD. On the old units, up through 69, the VR FEEDS POWER TO the field, with the other field terminal grounded. This means that to get the alternator (if good) to charge "full" output, you jumper known good battery power to the field terminal after disconnecting the green

BEAR IN MIND you may have a poor connection / high resistance / open in the charge path from the alternator stud to the battery. CHECK VOLTAGE when running with "full field" both at the battery AND AT the output stud of the alternator if you are not getting substantial voltage output. THEN check RIGHT AT the field terminal to be sure your jumper is actually providing 12V TO the FIELD

The ONLY DIFFERENCE on the 70/ and later VR is that in effect the VR controls the "grounding" of the field to control output. One field terminal has 12V connected, and the VR controls the current through the field via the green, which is the ground side of the circuit.

This is comparable to your dome light circuit. The dome light(s) are INSULATED (isolated) from ground just like the 70/ later field, and are fed 12V to one side. To activate the lamps, the door switches GROUND the switch lead to complete the circuit. The 70/ later VR is the same idea

BE SURE when "full field" testing, that you make certain the belt is tight, and an ear listening for possible belt slippage, glazed belt/ pulleys. Be sure to carefully bring up engine RPM. Usually you can HEAR the alternator high pitched whining, indicating it is working. If you are careful NOT TO SHORT the output stud or the 3x insulated diodes, you can "feel around" with a screwdriver when the thing is charging hard and feel magnetism acting on the screwdriver.