Problems with an inconsistent voltage regulator, won't charge until high rpms are reached but charges fine after that in my 1935 Dodge pickup.

Question:

I have a question concerning the voltage regulator on my 1935 Dodge pickup. It functions normally except for two difficulties. It doesn’t charge when the engine is first started, begins to charge when a fairly high rpm is reached, and then is fine even at low rpms. The second problem begins when the lights are turned on; the current flips in and out causing the headlights to flicker. I installed another regulator and the same things happen. The local generator shops indicate everything is OK, but don’t seem interested in helping. The truck has been meticulously restored, including all new wiring, but the electrical problems persist. What should I do?

Answer:

Based on all of the information you have provided, I think your problems may be the result of a poor voltage regulator ground. Meticulously restored vehicles often experience bad grounds because restorers put so much paint on all the parts and are so careful to thoroughly cover all surfaces and then don’t want to scratch or chip the paint when assembling parts and tightening bolts. Try running a separate ground wire from the battery (remember, your truck should have a positive ground) directly to the regulator. Other possible causes of your problem could be that the regulator was incorrectly polarized or not polarized at all, is incorrect for the truck (your truck came with an Auto-Lite regulator part #TC-4301A), is not a positive ground design (positive-ground vehicles like your truck require a positive-ground regulator), or is out of adjustment. Adjusting the regulator takes knowledge, patience and the right tools. If you eliminate the other possible causes and strongly suspect the unit is out of adjustment, take it to a technician who specializes in vintage regulators and have him clean and adjust the contacts, circuit breaker contact gap, circuit breaker armature air gap, voltage regulator armature air gap, and current regulator armature air gap. If at all possible, have these adjustments performed with the regulator installed on the truck.