The resistpr snaps into the rear of the heat distributor sheetmetal and the main harness connects to it. This regulates the speed of the 2 lower settings by reducing power by increasing resistance. The resister gets very hot in use which is why it's mounted in the airstream. In high speed the resister is bypassed sending all power to the motor. The following link has an entry showing what it looks like:
http://www.americanclassic.com/asp/...&iyear=1964&ytype=to&exyear=These are available everywhere, I imagine even Napa carries them. I used one for a Camaro in my 1960 GMC The only difference was the original snapped in and the Camaro used screws.
