Hello all. I've read a bunch of threads but not quite getting the answer we are looking for. My dad is just finishing up rebuilding a 51 Dodge Pilothouse truck. It has an inline 6 that purrs like a kitten. It is running the original 6 volt positive ground system. The wiring is a simple circuit and we've both double checked his hook ups and they match the manual but we know just enough to be dangerous about wiring. The truck will run for over an hour without dying (and probably would run until it runs out of gas). The battery keeps its charge the whole time. It starts every time without a boost. What we are stuck on is that checking voltage across the battery terminals when the truck is off, we get about 6.18 volts. With the truck running and generator hooked up through the regulator, we still get about 6.18 volts across the terminals. We expected 6.8 to 7ish volts? The battery dips to about 5.85 volts when you turn the headlights on. If you disconnect either terminal of the battery when running, the truck dies. We figure the generator can't be fully dead or the truck would eventually die from draining the battery, or at least draw down the battery voltage enough to notice. But we figured if generator was good, the truck would stay running with the battery disconnected? Are we over thinking this and the generator is fine? Or is it just barely ok? He hates to head out for a cruise night if the charging system is on its way out(or at least not working as reliably as a 51 system could be trusted). Thanks for any input.
Polarize the generator. Adjust the voltage regulator or replace it. This is assuming that the wiring is intact. Check all wiring first.
Not an expert , but I don’t think your generator is charging properly is the external voltage regulator good? Has it been polarized ?
Oh yah forgot to mention that we polarized the generator. The regulator just looks like a series of three relays to me. I didn't realize they could be adjusted but a youtube search shows how its done. We'll give that a try. Thanks
Try connecting a wire from the negative terminal on the battery to the field connection on the generator. Have the motor running at a fast idle. If voltage goes up to about 7 volts, the generator is good, look at the regulator.
Most of the time a generator puts out little or nothing at idle. Your output is probably fine once you reach 1000-1200 rpm
BING BING BING, WINNER WINNER CHICKEN DINNER. Generators do not put out much if any charge at an idle. you have to do as Stillrng said and get the RPM up to 1000 or better to see a charge. That has been the big issue with all generators from day one. At an Idle with nothing except the engine drawing power it might keep up with the needs of the engine but won't keep up with the demands of lights or other accessories. If you take off from a light and your lights get brighter life should be good.
This makes sense. We’re going to fire it up at night and turn on the lights and then step on the gas. It makes sense if the lights go brighter we are good to go. Thank you
You are correct in that the regulator looks like a series of relays. The first at the battery terminal is the cut-out relay. It opens when the generator isn't putting out more than battery voltage. The next two are the current regulator which limits the current the generator will put out, and the voltage regulator. You can tell the difference in that the current regulator has heavy windings and the voltage relay has very fine windings. However, first you have to determine if the generator is capable of charging. I don't know if this is an A circuit setup or a B circuit setup. On one you ground the field wire on the generator to get it to charge, on the other you send power to the field wir.
The Jalopy Journal
