The Stovebolt Site Forums The Shop Area The Electrical Bay 1946 Chevy 1/2Ton - 12v Heater Motor

I'll be converting from 6v to 12v. I searched some old threads, but does anyone have an updated 12v heater motor that is plugged and play? My 6v motor has a 1/4" shaft. I also have the defrost motor on top. Is that the same motor?

John, I had a nice 3 speed motor that would have probably fit right in there for you. I tried for over a year to give it away for the cost of postage and finally somebody took it. Many 12v motors from hang-down units, aftermarket units, etc might fit. I'd suggest removing your motor, measuring everything and looking on the large internet auction site. I would suggest a step-down converter (12v to 6v) however the amperage might be the stumbling block. Those 6v motors took between 5 amps and 10 amps and if there was extra drag from old/deteriorated bushings might take over that. A 12v to 6v step-down with 15 amp ability and a proper heat sink will cost you the same $30 a Chinese made 12v fan motor might cost...and you'll still have an old motor.

Thanks Jon. I was wondering about using a 6v with a voltage reducer since I'm converting to 12v. I can find 6v motors with a 1/4" shaft which would fit my fan. The 12v motors look to have 5/16" shaft, so that would mean drilling out the hole in the fan and I guess that would work. Most motors say "some modification may be necessary" - not sure how much though.

Almost all 12v motors will have a 5/16" shaft but that's an easy fix (as you said...drill it out by 1/16"). There are some inexpensive 12v heater fan motors that might work. Example: https://tinyurl.com/2u9tx2ck And a common speed controller like this one would be handy (you may not want the motor running at high speed all the time): https://tinyurl.com/mwc3evh6

Hope this is helpful, John.

There is one other option, John. A computer fan like the one shown in the link here might work: https://www.amazon.com/Nidec-dell-B35502-35-120x38mm-CN-0Y4574/dp/B00B87CTDA

It is a 12v DC motor, it puts out a fair amount of air and it only uses about a third of an amp at full speed. You would just remove your fan and the motor and attach this on top of the heater core. The key is would you have enough room to fit in 1.5" (that being its depth)?

Somewhere in the attic I have one of these I'd be happy to send for the cost of postage and I may also have one that might be a bit thinner...can't remember that for certain but I did save some of these from a thermoelectric project I did about 20 years ago.

This is the route I may take. Not running a voltage reducer to 6v motor seems like a good idea to me.

I agree. You want a nice predictable heater and not Mount Vesuvius.