The blower won't run in my '04 Monte. I recently had to replace the radio. I believe that is when it stopped working, but I'm not sure. I checked for any problems with wires at the control and behind the radio. When I check for voltage in the plug for the blower, it shows approximately 12v at all speeds without the blower plugged in, but nothing when plugged in. I hooked blower directly to the battery and it runs. Since it won't even run at top speed, I don't believe it's the resistor. All 3 fuses are good. Is there a relay to check? What else?

 

Any help would be appreciated. Wiring schematic would be great.