96 chevy cavalier heater control valve?

Question

Where is the illusive heater control valve?

Answer 1

The only "valve" i could think you are referring too would be the vacuum control on the back of the dash mounted heater controls. They do not have a valve in the coolant lines. The heat turned on or off by a vacuum operated door inside the heater box that merely closes and blocks the heat from escaping into the car. If you are having heater problems first make sure both lines running to the firewall feel hot/warm when engine is at temperature. Secondly you will have to find the actuators under dash on the heater box and make sure they are moving if not ck for vacuum.......