Hello,

I've noticed on my 89 Monty SWB 3.0 V6 auto, that the heat only gets hot when I'm on the gas. If I'm braking coming up to a stop light the air goes cold. I can hear some sort of relay, or motorized valve switching once I get on the gas again, then the heat is hot again. At the same time the temperature gauge floats closer and closer to the redline when the heater air is cold, but as soon as the "valve" or relay or whatever switches again, the temp comes back down to normal. This sounds like a combination of my truck not cooling very well, and some hvac related mechanism not getting the correct information. Does this sound familiar to anyone? Sorry if my explanation is lacking, it's a hard symptom to put into words. <img src="/forums/images/graemlins/smile.gif" alt="" />