Slowing down a heater motor?

[Vanspeed]

Hi guys, strange question but I recently installed a heater in a customers 49 F-1. It is a factory heater that has a 12v motor. Truck is 12v. He recently came by and asked if there is a way to slow the motor down. I used the switch pictured below because it looks correct for the truck. He thinks on low it is still too powerful. Any thoughts on how to slow it down? New switch?

 

[oldave57]

Does the switch you installed have a built-in resistor? In order to slow down the motor you would need to run the power through some resistance in order to slow down the motor. The switch in the link below has a built-in resistor.

https://www.kanter.com/products/ele...2DQKvYhNi1HYXxM1ihXBR5LhcT4VpMUUaAjK9EALw_wcB

 

[rotorwrench]

The F1 switch worked for a 6-volt motor and likely wouldn't pair well with 12-volts. It was common to mount a resistor board inside the heater plenum in the later 50s & 60s to protect it as a heat source and lower the heater blower rpm for a lower speed. These resistor boards are reproduced for some of the early 12-volt cars and could be adapted.