I recently discovered the (often frustrating) passion of fixing vehicles when I inherited a 15 year old boat with too many problems to afford. I moved on to cars soon after and have saved myself bundles making repairs on my 86 Larson, 1998 Mustang and 1990 Jeep. This latest one has me stumped though. The frikkin' vent system crapped out on me with no warning at all! Worse yet, in the gosh danged dead of a northeast August! How rude!

When it decided it didn't want to work anymore, the control lever appeared to "slip", meaning it won't slide properly into AC, Vent, Heating, etc. functions. I took off the dash and find no visible damage. I checked all my fuses, connection hoses, clamps and they seem fine. My theory is that its a wiring or motor issue, but as a rookie, its just a guess and wiring is an admitted weakness. Either way, its ticking me off! Ever drive a Fairfield County CT commute without air?

So anyway, as the subject heading suggests, I'm considering a good kick or five, or maybe a sledgehammer or something.

Please stop me with some sound advice.

Look at your vacuum tubes going to the vacuum canister inside the right front bumper. Thats if your Jeep is a current . Is it your vent position or the fan motor?

So you are not getting the fan to blow air out?
Then it's an electrical issue. Check the web site. It doesn't have '90 FSM but '88 or '93 should give you a good idea.

http://www.lunghd.com/Downloads_and_Links/Downloads.htm


If the fan is working fine but the knob is not sliding to select a vent:
The controller is very simple. All you have to do is to take it apart VERY carefully (don't break any latching tabs). If you do break it, then you'll have a vacuum leak. You have to re-enforce it tight. You will see how simply it is in inside. Place the knob piece back on the right place and make sure it slides. Also make sure the plastic pieces on the back were correctly installed. Then seal it back up.

Good luck!