heater control valve location on 2001 Ford Expedition

i am having problems with my heater front and rear and i changed the thermostat but it did not help. the dealer told me that the blend door motor could be bad but i think that it is a control valve. can you tell me where the front and rear heater control valves are located.

any one have picture of location
1 more answer
You might find a free repair manual here: or go to or and get an online repair manual subscription.