Usually there are two ways the heater systems work.
One - The heat from the engine is regulated through a valve that is opened by vacuum, cable or motor. This opens the valve allowing hot coolant to flow through the heater core.
Two - The hot fluid continuously flows through the heater core in a plenum. The plenum is thus usually hot and awaits the door to open to let out the heat.
You mentioned that the cables appear to be fine. Doesn't your repair manual show a valve? I don't have access yet to a maintenance manual on that model.
Monday, January 8th, 2007 AT 9:53 AM