heater/ac switch will not run on 1,2 or 3?

2004 CHEVROLET SILVERADO
173,000 MILES • 4.3L • V6 • 2WD • AUTOMATIC
Avatar
RAHLO18
  • MEMBER
  • 1 POST
The control switch only runs on 4 & 5. Will not run on 1,2 or 3?
Sep 2, 2015 at 5:18 PM
Advertisement
Avatar
JACOBANDNICKOLAS
  • CERTIFIED EXPERT
  • 110,175 POSTS
Most likely a bad blower motor resister. Check that first. Here is the location you should look for burn mark or signs of overheating on the resistor. If the resistor is okay I would replace the switch. Check out the images (below). Please let us know what happens.

Images (Click to enlarge)
Attached Media
Attached Media
Attached Media
Attached Media
Sep 2, 2015 at 7:20 PM