anybody have an idea what's wrong with my heater/ac, it only works on 4(hi). When you turn it the lower settings (1-3) nothing comes out.

 

I have the same problem with my 2007 Colorado. Only now and then it works, only more often it doesn't. It's very annoying. Any ideas?

 

yeah had someone email on another forum. .

"Sounds like a bad blower motor resistor. The blower motor resistor uses multple resistors inside to vary the amount of voltage the blower motor gets. In the low speed, it cuts the volatage the most and also generates a high amount of heat, in med, it cuts the voltage a little less and in high, the resistor is basically bypassed and the motor gets whatever the system/battery voltage is. The resistor is usually mounted near the fan in the fan housing. It is usually held in with two screws and has 4 or more wires on it, depending on the amount of speeds. It is in the housing as it uses air from the fan to keep it from overheating."

So I bought one and haven't put it in yet

 

Was that the fix? Having a similar issue in my 07 Colorado.

 

632bbc, could you update us with what it was that fixed the issue for you? Thank you.

Jeff Morris, Chevrolet Customer Service

 

I guess I could update mine too. I found another thread on the board that mentioned that it could be something as simple as the electrical connection. Took 20 seconds to troubleshoot after that. With the car running and fan switch on either 1, 2, or 3 I reached under the dash on the passenger side and jiggled the wire connector and the fan came on immediately.

I haven't actually fixed it yet but it should be relatively painless and quick when I do.

 

Mine has the same problem, i can only have it on speed 2 and if i switch it to another speed it would turn off. some friend found that a connecter under the dashboard in the passenger side underneeth by the floor there is a connecter that is for the ac controls and he found out the the connection was bad so thats why it turns off when i switch it to another speed. I havent bought it yet because ive havent had the money for it and i dont know how much it cost. Ill update this post when i buy it and install it. Hopefully it works and it can help the rest of the people.

 

Happened on my 05 and I replaced the resistor and has been fine since

 

you may also have to change the connector socket to the resistor.... check and be sure that the socket is not charred otherwise you will keep burning out resistors....