So I'm getting very aggravated with my hvac. My blower motor isn't switching on any speeds. My brother also has a Cobalt and I've tested my climate control switch, blower resistor, and blower relay on his and they work fine. I bought a blower motor from the junkyard and tested it on his car and it worked perfectly but on mine no dice... All the fuses are good. Correct me if I'm wrong but there are 2 fuses and a relay in the car and 1 fuse for the bcm under the hood. My blower motor is getting power but for it to turn on the red wire has to drop voltage. I tested on my brothers car and seen that the higher the fan speed the lower the voltage will be on the red wire, while the black wire remains a constant 12. Both wires on my car are staying at 12 volts when the car is on. Any ideas for the fix?

 

sounds like the resistor is bad.

 

I thought that too until I tested mine on my brothers car and put his in mine

 

Control unit?

 

If you're talking about the unit that selects vent position, blower speed, and temp then yea I swapped in my brother's and one from the junkyard with no luck. And I tested mine in his car and it worked fine.

 

Problem solved. Took it to the dealer and $175 later they fixed a melted connection near the fuse box on the ground side that's why it wasn't blowing any fuses.

 

Think a hot wire back there could have melted to? Im having similar problems but my motor isnt getting any hot signal..im getting a new contol panel from a salvage yard tm but doubt thats my problem because i hotwired the blower motor and have 0, 1 ,2,3,4 ac on and off but no recirculation which is kinda wierd..works for a bit anyway untill it blows a 25amp fuse i put in..seems like theres a short somewhere but its not blowing fuses or relays @bcm, unless the motor just draws more than 25 amps

 

A binding motor can easily overheat wiring and blow fuses. Try replacing it and see how it goes. 25 amps is a lot for a properly working blower motor.