The Stovebolt Site Forums The Shop Area The Electrical Bay Hot Generator

I ran my '51 3100, with a '53 235, for about 15 minutes and the generator got very hot to the point thr paint was buring/smoking off. I just had the generator rebuilt. They said it was a 12V and gave me a new 12v regulator to go with it. This was a generator/starter reputable repair shop and they do many cars.
Any ideas what would cause the overheating.

I would be callin' that repair shop pronto.

did you/they oil it? i would check that out first

I once had a bad, new, voltage regulator run the generator so hot that the solder at the windings melted.

As described here.

Here's where the hot solder goes when it's slung off of the armature ...
< TWIN SOLDER TRAIL >

If its getting hot enough to burn paint off then its way overcharging. Only one thing can cause it to overcharge, the regulator. There are two different regulators available now, If you purchased one that was made in India it will have it on the regulator cover...they are junk. If you have a made in USA brand it will be stamped into the metal. Take a look at which one you have, if its the India one its possible it could be bad from the start. I have never had any issues with the made in USA ones. Take a look at the picture Lonnie posted and look inside of your generator to see if any solder was slung out of the pins. If they did supply you with a faulty regulator and it damaged the generator then they should make it all good.

Kennetw-you mention that the generator is most likely overcharging, but when I checked the battery, after the 15 minutes of running, it was at 8-9 volts and would not crank the engine over.
I started with the battery fully charged. I called he generator shop and they said to bring in the generator and regulator. I have not had a chance to see where the regulator was manufacturerd but will do so when I pull out both items.

ok, so how is your battery? Take it with you and have them charge it again and put it on a load tester. The regulator controls the generator but if the battery has issues and not holding a charge then the generator could be charging to much. The generator is not made to constantly charge at full capacity on a continuous basis and you will get the same effect of a generator over charging. Something is going to eventually give and nine times out of ten the solder in the armature pins is going to be the first to go.

I brought my generator, regulator and battery to the repair shop that did the rebuild. They did a load test on the battery, which checked out fine. They bench tested the generator which was working properly. It turns out the regulator was stuck on and caused the generator to overheat. I had the rebuild done 10 months ago, but the warranty was only for 6 months. Despite the fact that I have only run the truck for 15 minutes in the last 10 months, it did not matter for the warranty, I had to buy a new one(at cost). The regulator did not have a manufacturer name on it, but it did have "Made in USA" stamped on it. I am concerned about the soldier, but the truck seems to running properly, at this point. Thanks to everyone for sharing your knowledge and suggestions.

Regarding the regulator, I am guessing that the cover was made on the USA!