Alright, here's the deal. I have an 83 c20 (4 door, long bed, 454) and the blower only blows on high. Now, you're thinking it's the resistor - it's not. Replaced it twice, and have tested the continuity. The fan switch and relay have been replaced as well. All that I can think of now is that there could be a short in a wire somewhere and that's causing no voltage to be received to the blower.

Any thoughts? What wires should I trace out? Any schematics?

Thanks!

 

There are two circuits feeding the motor. One for high speed and another for all lower speeds.

On the lower side, first thing to check is the fuse of course. If you've already replaced the resistor, then the problem is in the switch. Make sure the temp slider isn't on "MAX cold", as it over rides the fan switch and puts 'er on high speed.

Otherwise, switch is bad.

Allan

 

From what I can find, there is only one fuse and it supplies the high blower. All the fuses in the box are good. The switch is new also, and it isn't on max cold. I've tried all positions.

I'll pull the instrument bezel and see if I have power at the appropriate places.