AC/heater blower only works on setting number 4

2005 CHEVROLET COLORADO

100,000 MILES • 4 CYL • 2WD • AUTOMATIC

BIGKAJ

MEMBER
1 POST

The AC/heater blower has four speeds (1 through 4). The only speed the blower works on is the 4 setting. I've had problems with this blower switch before. I had the dealer replace it before. I'm wondering if I can change out the blower switch myself? Apparently this is a design flaw in the blower on this vehicle.

Please advise.

Jun 12, 2019 at 7:50 AM

SCGRANTURISMO

✓ASE Certified Mechanic
4,897 POSTS

Hello,

This doesn't sound like a problem with the blower motor speed switch, but the blower motor resistors. The blower motor controls the speeds that it operates at by running the electricity sent to it through a series of resistors. So if you want it to run on 1 the electricity going to the blower motor will have to pass through three resistors, 2 two resistors, 3 one resistor, and finally 4 no resistors. I have included in the diagrams down below the complete factory removal and installation instructions for the blower motor resistors in your vehicle. Please go through the guide and get back to us with what you are able to find out.

Thanks,
Alex
2CarPros

Images (Click to enlarge)

Professional Diagram for 2CarPros Members
Click here to log in and view diagram.

Jun 12, 2019 at 10:44 AM