I'm still trying to get my heater motor to work. The motor is new and the car is a '70 originally with A/C. Now has an A/C delete plate. I kept the high speed relay and resistor assembly and with everything plugged in, no motor operation. I don't know if anything worked before, I bought the car with the A/C box removed and the wires hanging. Do I have to have the vaccum hooked up for the motor to run? Is there a vaccum switch in-line with the power to the motor?

pretty sure vacum is only to operate actuators for demist, floor, vent, hot & cold etc. and shouldn't affect the blower motor but I'm not 100%. Trace power with a test light from the fusebox to the resistors to the switch and out to to motor, and I think there maybe an in line fuse on the firewall ?
Dave

Thanks for the reply. found the in line fuse and it's o.k. I need to find a way to check the fan switch in the dash to make sure its working. Any anyone know which wire supplies voltage to the switch. I'm assuming one wire is supplied with constant voltage and jumps that power to the corresponding fan speed wire that goes to the resistors and on to the fan motor? If I could figure out which one is constant power I could manuely jump from speed to speed tap bypassing the dash switch to find out if its the problem?

there is no power there unless ignition is on
Dave