I've got a 2004 Colorado LS that started doing that almost a month ago i guess. It is intermittent, I can't pin point it to anything like leaving the AC on or off or at any particular level, it does it with ac or heat. I assume it is either the fan motor or the switch. I haven't been able to take it in to the dealer because I'm never near the dealer when its doing it.
Plus sometimes if it starts doing it right away when i get in the truck I can switch it between 3 and 4 real fast and it will start working. This is why I think its the switch. Sometimes though I will mess with it for 20 minutes and get nowhere only to park it and come back 5 minutes later and its working. It is very strange and VERY annoying. If you figure it out let me know and I will do the same (If I ever take it in to have it looked at).
The last time it did that I tried to pop the dash cover off and look at the switch but it's all clustered in with the other 2 knobs into one unit so I can't investigate a whole lot.
A forum community dedicated to all General Motors truck owners and enthusiasts. Come join the discussion about performance, lift kits, wheels, tires, modifications, troubleshooting, maintenance, and more!