heating/AC problem

[ddmeli]

The heating/AC is stuck on defrost. When you switch the controls to any other setting it just stays on defrost. Normally its kept on the upper and lower vent setting with the AC on. The upper vents use to go on and off. The control itself seems fine. Anyone encounter a similar problem or know of a manual with a good layout of that system?

Thanks

[JDPascal]

I believe that the defaut mode is defrost when vacuum source is lost.

Check the vacuum connections on the intake and someone reminded me that there is a vacuum reservoir too. It's probably up near the rad and to one side. I know some one else will tell us for sure.

Which year jeep is it - the 2000 or the 97??

JD

[ddmeli]

It's a '99 and all I can say is that I'm glad someone had the foresite to make defrost the default upon failure. Thanks again.