I havea 2003 S-10. I first noticed problem this past summer. My A/C was working just fine. I pulled into my wifes work and stayed in the truck while she ran inside. Waited maybe 10-15 minutes and the A/C quit coming out cold. Was just normal air. This lasted all the way home (20-30 minute drive.) But then later that day when I went to work and it was working fine. A few weeks later my check engine light came on and has been on ever since. (Haven't had time to check for a code on it) When the weather turned cold and I starting using the heat I noticed that my truck temp seemed to be running cooler than usual. The heat will work for a few minutes then start blowing not cold but lets say barely warm. Then it will start blowing hot for a fewminutes than back to semi-warm. Some days it will stay warm all the way to work and some days it does the back and forth thing. Anybody have any suggestions on what it could be or what to do?

Thanks
Matt

 

Sounds like you have a problem with the temperature setting inside the vehicle. The **** that sweeps from hot to cold may be losing connection or have a high resistance connection due to corrosion.