I've been reading through this forum and my problem seems similar to the blend door issue. I have a 99 F150 my symptoms are that the A/C works with no problem if I am not in gear or in gear just idling. As soon as I start driving it immediately starts blowing hot air and will not stop unless I turn off the A/C. Does anyone know what could be causing this?
Thanks in advance for any help.

 

Sounds like you have a compressor performance problem. Put some guages on it and watch the readings to see how much they change when the RPMs come up.

 

Look under the hood and see if the compressor clutch is engaged while the air is hot.

If so, the blend door is probably kaput and is flopping around when you take off or stop.

Also, clarify what "hot" means - loss of cooling or the air is actually heated.




Steve