Thanks for your reply. My situation is somewhat unique. The truck is already 12 volt, and the heater motor has been replaced with a 12v unit. But the motor spins at an ungodly high r.p.m. I want to put a 12 to 6v. reducer to the motor and cut the r.p.m.s. Not sure if the old switch has a reducer on it, but I think you're telling me I need that also? It makes an incredible amount of harmonics inside the cab and I want to install a radio a bit later. It would be nice to actually hear it!
