Lost my defroster setting

[97teejay]

I have a 97 Wrangler TJ, with a manual 4.0. I know the air systems work on vacuum and i lost my only my defroster setting. Any body have pictures or a diagram of the vacuum system?

I was just going to pull the dash apart and start from the switch and work my way thru the system but if anybody has had a similar problem and could tell me a good place to start to save some time that would be great.

Thanks for the input!

 

[TerryMason]

I had the opposite problem.

Take a look at this thread and see if it helps
http://www.jeepz.com/forum/cj-yj-tj-jk/23305-only-defroster-works.html

 

[Crazy4diesels]

The thread Terry mentioned has a lot of good info in it. Failing that, I'd check the vacuum powered dampers that direct the air through the heater box. Working through the glove box hole you can see some of the plumbing. You might have to pull out some of the "center stack" (radio, heater control panel) to get at the rest (I'm not too flexible any more so I can't do "dashboard diving" like I used to - you might be able to get in there better than I can!!). Try to verify that none of the little plastic arms have broken off of the dampers. The arms are where the diaphram pull rods connect. All of this stuff is fragile so use caution as you work in there. Also check the diaphrams for leaks (you can use a little vacuum hand pump or even just use a length of vacuum hose and suck on it). Best of luck - John

 

[SteelHeadz]

If you only lost the Defrost mode, chances are, the problem could be on the Actuator or the Control head unit.. It is not nescessary to remove the Dashboard to access the Vacuum lines to the control head.. you can check the lines thru the opening behind the glove box after you remove the glove box door. It's a multi colored vacuum lines that runs the network of actuators for different Mode settings..
Location and Removal of the Defrost Actuator.
DEFROST/DEMIST DOOR

1. Disconnect and isolate the battery negative cable.
2. Remove the steering column cover and knee blocker as described in Instrument Panel Systems.
3. Unplug the two actuator vacuum lines from the actuator Defrost/Demist, Floor, and Panel Door Vacuum Actuators
4. Remove the push nut securing the actuator arm to the stud on the defrost/demist door lever.
5. Pull firmly outwards on the actuator to release the snap-fit actuator mounts from the mounting stanchions molded into the heater-A/C housing.
6. Remove the actuator from the heater-A/C housing.
7. Reverse the removal procedures to install. Be certain that the push nut is reinstalled.
8. 

 

[97teejay]

Wow, thanks guys for all your suggestions, tips, and direction. Hopefully i can get this fixed and drive the jeep again soon (i had to park it because the windshield kept icing up) i will keep you posted what I end up finding /come up with.

Many Thanks!

Paul