EATC Stuck on Defrost????

[architect-builder]

Wifes 05 Excursion. The eatc does not seem to be working. Stuck on defrost, will not change to any of the other vents. Anyone seen this problem? 4x4 works, so I am assuming not a leak. checked fuses, etc.... At a loss.

Barrett

 

[DaveBen]

A loss of vacuum will cause the heater/ac to default to defrost. The vacuum door does not open (or close) to any other setting without a vacuum signal. Probably a vacuum line that is disconnected.

Dave

 

[maladosteo35]

I got this one

Wifes 05 Excursion. The eatc does not seem to be working. Stuck on defrost, will not change to any of the other vents. Anyone seen this problem? 4x4 works, so I am assuming not a leak. checked fuses, etc.... At a loss.

Barrett

Ok, this same thing happened to me. it is a lack of vacuum problem. pop the hood. walk around to the passenger side of the truck. look along the back edge of the body where the hood meets. as you trace along from the passenger side to the middle, you should see a small plastic device, black, about as big around as a red bull can. it has a nipple on it that faces the front of the truck. I bet you can see the nipple because the small vacuum line that goes into it has popped off. find the line, stick it back on and check your problem. after you're sure you're fixed, then go ahead and fix the tube to make sure it doesn't pop off again.
good luck,.

 

[architect-builder]

Well, it's been a while, I kept forgetting to post results, sorry.

After checking every line, etc..., I broke a got a vacuum tester/pump. And, It turned out to be the vacuum pump nota puting out anything (knew a few like that in college....).

Guess it still lasted longer than the one on my truck.... B