The Stovebolt Site Forums The Shop Area The Electrical Bay 6V wipers on 12V

I bought a universal reducer with the intention of using a rebuilt 6V wiper motor in my '54 GMC. I thought it would be as simple as wiring it in line. However the instructions show six wiring diagrams using multiple reducers for different amp rated accessories.

Anyone know the amp rating of a '54 GMC wiper motor or how to determine this?

Are any of you running 6V wipers using a reducer with success?

I suggest trying it out on the tap meant for 8 amps. Measure the voltage across the motor when it is running to see if you need less or more voltage reduction. A 6 v blower motor draws around 8 amps.

Sounds about right. I think most 12-volt wiper motors run at about 4 amps, so it makes sense that a 6-volt motor runs at 8 amps.

You will want to drop the working voltage at the motor from about 13.5 volts to 6.5 volts when the engine is running, for a difference of 7.0 volts. For electricity, V=IR. If V=7 volts, and I=8 amps, then R=V/I= a 0.88 ohm resistor. I'd probably start with two 0.5 ohm resistors in series (1 ohm total) and see what happens. Each resistor needs to be rated for 50 watts.

Click here for Resistors.

This is an educated guess. Others might have better information.

Cletis, I have similar situation with my 6V wiper motor for the 37. I'm watching this thread hoping to put all together and fix mine.

Keep the posts coming.

Jeremy

After further study I have determined that a resistance type reducer would not be practical for an electric motor. A solid-state reducer such as this one is the proper solution.