The Stovebolt Site Forums The Shop Area The Electrical Bay ron francis vr4 voltage reducer

I installed a ron francis vr4 voltage reducer to run my heater when I converted to 12 volts, it worked well for a couple of years, but the other day the heater blower was going really fast, and then the fuse blew. I now have 12 volts to the heater. While looking at what happened I noticed the ground to the reducer was kind of loose, could that have fried the reducer? I really, really don't want to remove that heater again to install a 12 volt motor, the reducer was expensive enough.

I wrote a long reply and my server ate it! Use one of the GM speed control resistors that mount in the air box and pick out the right combination of connections to get the blower speed you want. Cheap, simple, and available at any FLAPS or on Ebay.
Jerry

I think you are saying that you have a 6 volt heater motor and a 12 volt system. If that device was a 3 terminal regulator and the ground came loose then it would certainly malfunction. I used a 1 ohm 50 watt resistor in series with my heater when I converted to 12 volts. Most of the truck part vendors sell them. They should be mounted on some sheet metal to dissipate heat.

Looks like that voltage reducer cost twice (or 3x) the price of a 12V motor. If the ground isn't the solution just buy the right motor instead of another voltage reducer. Or a cheap resistor as Jerry suggested.

Info on heater motors
https://www.stovebolt.com/ubbthread...6055/Easy/cheap_heater_blower_motor.html

A circuit with a resister will show the maximum voltage with no load on it. Just like an ign. coil. If the points are open so there is no complete circuit the voltage at the coil will be 12 volts. With the points closed it will be 7-9 volts. You may have bad motor. Run a jumper wire from the bat. to the motor wire & see if it will run. Running it on 12 volts for a few seconds won't hurt it. If the motor is good test the reducer. Make sure your reducer & the motor has good grounds.
George