My '01 Tahoe stops blowing cold after idling for 5 min or so. Not just less cold, I mean it blows hot. It blows very cold again after driving for 5-10 minutes. It has also done this after driving if I stop and shut it off for a short time. When I start it up, it has to be driven at 30 mph or more for about 5-10 minutes before it stops blowing hot again. Any suggestions before I take it in for service?
Fred
