I have a 2003 silverado 1500hd, and the fan only works on 3 4. Any advice as to what the problem may be?

I have a 2003 silverado 1500hd, and the fan only works on 3 & 4. Any advice as to what the problem may be?

you need a new fan switch. mine only works in 2,3,4 and 5. 2,3 are getting slower

First off welcome to the site..I would say your resisters are bad..Its also possible that your module is bad too..Im sure others will chime in to help..If you need anything else just ask

Thank you...

My friend has a 1999 Prizm and the fan would only work on high. I googled it and it was the resistor. On her little Prizm I ordered the part on-line from Rock Auto, used a socket to remove the resister unit, pulled out the bad resistor (just like pulling a memory card out of a pc), plugged the new one in, wrenched the unit back in place and it works like a charm. The unit was under the dash on the passenger side. Didn't have to remove anything but the little plastic trim door, pulled the carpet back and there it was. Ya' gotta love Google...if 2 chicks with a socket wrench, a couple of beers and a print out from google can fix a little chevy, I'm betting you can fix a big chevy .

Your blower motor resistor is under the glove box, very easy to get to. It has 2 harnesses going to them: one with a red and a black wire; one with 7 wires.

Put your fan on one of the non-working speeds, key on, and wiggle the 7 wire harness. If that causes the fan to work intermittently you are in need of a blower motor resistor AND a new pigtail (harness). The last one I looked at, the connector welded itself into the resistor. Look for burnt wires going into the connector. This is very common, and not just with Chevy, but Chevy is about the easiest to work on.

If nothing seems wrong there AND you have rear a/c, check the rear fan switch on the front dash. I've seen this with Astro vans alot, though I haven't seen this in trucks yet. It can't hurt to look.

Good luck.

I have just entered a post looking for information, but what you described here exactly is what I thought was needed to be done. I have removed the resistor or what I called the rheostat, and will need to get a new 7 wire plug as well. Great forum..

The rheostat is the switch, the resistor is under the p/side dash.