Help Please....Heater blows only cold air

My 2000 Ford Expedition blows only cold air with the heater on. This is after the car is well warmed up....Thanks for any help you can provide.

Dave

there might be a flap under the dash that isnt closing letting cold air in rather than hot. I had this happen to my aerostar van. they had to screw it shut or rip out the dash and fix it. It worked fine. clogged heater core might be anothe problem.

there might be a flap under the dash that isnt closing letting cold air in rather than hot. I had this happen to my aerostar van. they had to screw it shut or rip out the dash and fix it. It worked fine. clogged heater core might be anothe problem.

Thanks for the reply, do you know where under the dash this might be in the expedition, and what I can do to make it open? Also, the temp guage reads normal, right in the middle when the car is warm.

We are having the exact same problem with our 1998 Expedition. I tore apart the entire dash, took about 2 days, and found that the blend door was working fine. It was located basically behind the glove box. But the only way to get to it is to remove the entire dash ("instrument panel"). If you are getting lukewarm air with the fan on low and when you turn the temprature control to cold and the air turns colder, it is not the door. It is something else. Possibly the heater core not working properly, which back flushing might resolve. Other than that, ours is still not working either. We are going to try replacing the vacuum control switch (the controller that you use to change the outflow of air from floor to defrost to panel etc.). We'll see if that does it.

We are having the exact same problem with our 1998 Expedition. I tore apart the entire dash, took about 2 days, and found that the blend door was working fine. It was located basically behind the glove box. But the only way to get to it is to remove the entire dash ("instrument panel"). If you are getting lukewarm air with the fan on low and when you turn the temprature control to cold and the air turns colder, it is not the door. It is something else. Possibly the heater core not working properly, which back flushing might resolve. Other than that, ours is still not working either. We are going to try replacing the vacuum control switch (the controller that you use to change the outflow of air from floor to defrost to panel etc.). We'll see if that does it.

Please see http://www.automotiveforums.com/vbulletin/showthread.php?t=325775

It could be the same problem as your only in reverse. Please read down the post for a possible fix.
Alex-