A/C blower changes from vents to defrost

I have a 1997 Jeep GC, 5.2L. When the A/C is on, recently a condition occurs where the air is selected to blow out of the dash panel vents, but sometimes redirects and comes out of the defrost dash top vents. It seems to happen when I step on the gas. Stepping on the gas causes the redirect from panel vents to defrost vents, and once I get off the gas, the air redirects again to the panel vents.

I have chatted a bit with a few folks about this and it seems that the general concensus is a vaccuum problem. So, where would I look? How do I troubleshoot this?

Thanks!

Brian

try this link.

http://home.sc.rr.com/janet/TSB/24-01-96A.htm

Sounds like what is described in the S/b

Default mode for the heater is the defrost position when the vacuum is low.

this S/b lists a kit from jeep that has a check valve to maintain vacuum in the heater control unit during acceleration.

The home page for that S/B is here

http://home.sc.rr.com/janet/

enjoy

JD

JD,

Thanks. That is the EXACT problem. And I am sure this fix will remedy. I'll be installing this later this week. I bookmaked the page. Thanks for the info.

Bull

Does anyone have any current info on this, the web links are no longer working. I have a 1999 Jeep GC, 4.0L. When the A/C is on, a condition occurs where the air is selected to blow out of the dash panel vents, but redirects and comes out of the defrost dash top vents.

Any info is appreciated!

Thanks,
Ninpo23

Try this link which worked on May 26, 2010.

http://dodgeram.info/tsb/1996/24-01-96a.htm



Does anyone have any current info on this, the web links are no longer working. I have a 1999 Jeep GC, 4.0L. When the A/C is on, a condition occurs where the air is selected to blow out of the dash panel vents, but redirects and comes out of the defrost dash top vents.

Any info is appreciated!

Thanks,
Ninpo23