I have an 2002 Lariat 4.6 and the cliamate control keeps jumping from defrost to the vents on Max AC. It blows cold either way, but it seem it varies which vents defrost or panel vents it comes out of.

Sometimes, it seems this only happens when I have the foot on the gas

any ideas?

 

Sounds like a vacuum leak somewhere, foot on gas= less vacuum, and it will go to the default position which is defrost. Also, this is the 04-06 forum, try the other forum for a better repsonse.

 

If you have it on auto climate control mode, it might just be choosing itself where to blow air. My auto climate control on my 04 will sometimes come out of the vents in auto, other times on the floor, etc.

 

Going to move this one up to HVAC.

 

first off, welcome to F150online!

More then likely, like the first guy said above, you have a vacuum leak. Or worse case scenario a problem with the Blend door (lets hope not because to replace that blend door, the hole dash has to come out)

You might want to take it into the dealer if it bugs you enough that air varies through different vents, but you probably have a vacuum leak. I have the same problem right now I'm trying to hunt down, but I'm able to hear the vacuum leak, do you hear any air whistling of air inside or under the dash?

 

I am experiencing similar problems...ac only blows through window defrost vents. Ford dealership claims internal solenoids faulty on climate contol panel. New unit 496.20 plus labor. Sound a little pricey to me. Any ideas on an alternative?