70 Nova - blower motor only works on low

I have a 70 Nova, 350 with partial A/C (most has been removed) The blower motor only works with the switch in one of the two low speed positions, and even then at the same, very low speed. If you move it to a higher position, the blower stops altogether. How do I determine if it is the blower motor itself, the switch or the relay (and where the hell is that relay hiden???)

Much thanks from a cold dude

Have you thought about checking the blower motor resistors? I would say, however, since low speed works, you can rule out the blower being bad. Second, since high and the next speed down doesn't work, you can pretty much rule out the resistors, because high doesn't use the blower resistors. I'm betting on the switch being bad, based on the info you gave me....

I have a 70 with the basic heater. In my car the resistor is bolted to the heater box on the inside of the car. Just follow the wires