Dash AC intermittently blowing cold air, then hot
My Dash AC blows cold air when the engine is cold, but after it gets warmed up it blows hot air. I assume that it has a Evans Tempcon Electronic Coolant Valve that can shut off the coolant to the heater core when the dash AC is turned on. There is also a Vacuum Pot on the bottom of the AC shroud which I think operates a flapper blending door between the heater core and the AC. With the engine cold and idling, I get cold air. But going down a flat highway engine not under load I get hot air. Pulled into a rest area and with engine warm, and at idle I still get hot air. Is it the Evans Coolant Valve that is bad, or something in the controls. I have heard that some replaced the valve with a manually operated ball valve to use during the summer months. Can anyone shed some light on this and is there a way to check it out.