When the car is idling even with the engine hot the heater blows cold air.
At highway speed it blows hot ait again until I stop. I ran the Climate Control self test as described in the FSM. All systems preformed well except the discharge air temp doesn't change. I think It may be the Automatic Amplifier but I'm not sure. What else can it be? Can anyone please help me with this problem? I have 195K on the car but have taken excellent care of it since day one.