The Stovebolt Site Forums The Shop Area The Electrical Bay 12v regulator

I am switching my 1952 1/2 ton to 12 volts and running a generator. I wanted to make sure the new 12v regulator would mount in the same location as the 6v unit so I went to the local NAPA. I asked for a regulator for a 1955-59 Chevy truck. They told me there were 5 choices, matched to the generator output. Anywhere from 30-50 amps. I put a new front bearing and brushes in my generator and didn't get any questions about different models at that time and there are no tags left on the generator so I do not know the output.

I guessed the 30 amp model was what I wanted. Napa has two voltage regulators for the 30 amp generator. Both made by Echlin and both made in the USA. One is 3 times more than the other (less than $30 vs. almost $90). The parts man tells me the internals are different.

To me the voltage regulator is just a black box. I can polorize a generator and I have freed up stuck points but that was decades ago. Not knowing anything about the differences I went with the more expensive unit. Am I wasting money? I can always exchange it but I am willing to pay for the more expensive unit if it is more reliable and better made. Any opinions about this are much appreciated.

Chuck

Got any part numbers available? I can't imagine a reason for that much price difference, particularly for the same charging capacity. There is a heavy-duty double contact regulator, but it was designed for use with the 50-55 amp Oldsmobile and Cadillac generators with ball bearings on both ends. As long as the current regulator can control the generator at 30 amps, I'd pick the lower-priced regulator for my own use. You can replace it three times for the cost of the pricey one. Regulators just aren't that complicated! Is there a different warranty, maybe?
Jerry

Thanks for the response Jerry. The part I got is a VR122. I cannot figure out which of the 400+ voltage regulators on the NAPA site is the $30 model. I don't know how to filter their info and it comes up empty if I ask for a single year model.

Anyway, if you say the cheaper model is fine that is good enough for me. They said it was no problem to exchange it. Is the 30 amp generator the most common 235 generator?

Chuck

My Motor manual lists a 25 and a 30 amp generator for Chevy from 55-62. Olds, Buick, and Cadillac specifications show generators up to 45 amps. A note about the Chevy 30 amp system indicates that it uses a "double contact" regulator and cautions against grounding the field circuit with the field wire attached to the regulator. Apparently, the 25 amp generator does not use the double contact system. That should be easy to check by removing the regulator cover. The 2-contact setup will be behind the "F" terminal. The 30 amp generator will work OK with a 25 amp single contact regulator, but you'll lose 5 amps of charging current against a very low battery. Not a problem unless you have a lot of high current draw accessories, or you're in the habit of leaving the lights on with the engine stopped and running the battery low. Good luck!
Jerry