Boy, this blows -- not hot air, though

Question: I have a 1999 Ford Expedition that has a dual air system. The rear heat doesn't work -- it just blows cool air.

[San Diego Brad]

Oscar,
The problem with your rear heat in your expedition is probably the blend door controller. Do you hear a clicking or thumping noise when you try to turn the rear heat on?
I and a lot of other expedition owners have the same problem and the fix is to replace the controller. It is located under the rear passanger side interior plastic wheel well cover. And can be accessed by removing the storage tray and cup holder that snap into the wheel well cover. The controller is a small white plastic box about 2.5 inches by 3.5 inches with three wires plugged into it.

[paul]

I have a slight problem my 98 expedition when i turn on the heat after the engine is hot the heat comes on hot and then goes warm everything seems fine holding coolant and thermostat was replaced dont knpow what to do pls help