the heater on my 2000 expedition does not blows hot air,it blows cold air.
Wat problem should i look for? thermostat or something else?

 

sounds like a blend door problem or an actuator. that is all behind the dash

 

My 200 Eddie Bauer is doing the exact same thing. No coolant or condensation in the passenger compartment or anything obvious. It just quit blowing hot air.

The engine warms ok. Coolant levels are ok. I replaced the thermostat to no avail. Still doing the same thing.

People have mentioned blender door or actuator. I'm still in denial because I know what a bear it can be to take the dash out, and then reconstruct it where it won't rattle all the time.

I'm hoping for a mild last half of winter, and I guess I'll deal with it until spring.

Anybody else have any ideas?

 

that is the only idea