Air output turn knob not working :(

kis86

New member
The little turn knob to change where the air comes out just stopped working this morning. It's about -20 degrees here, so something must have broke...but no snapping noises or anything, it just turns really easily and nothing changes. Lucky I had it on defrost from yesterday!

What do you think I need to do to fix it?
 

Check to see if the knob its self is broke. Pop it off, it should be shaped like a D. Usually the knob will crack causing the D to slip around the rod rather then turning it. You can try a different knob or use a pair of plyers and see if the rod turns and still adjusts your air flow.
 
If it is cracked it can be fixed with a dab of super glue. That is what I did to mine. Just wait for it to dry before putting it back on.
 
If the knob is not broken then you have one of the common early TJ problems.
A bad contact the A/C control module, the first trick is to pull the module out and clean the contacts with spray contact cleaner.
There are four screws holding the beauty cover on around the A/C / Stereo. Two in the defrost vent and two next to the ash tray. The beauty cover is also held on to the dash by some push through rubber mounts, a gentle pull and it should come off. the A/C module is held in by four screws which you should see and one gang plug on the back.
Clean the contacts and allow it some time to dry before hooking it back up.
If this doesn't work (didn't on mine) then your only hope is finding one in a local junk yard or 80-100$ from your local stealership.
 

I pulled off the knob, and it isnt broken...it is turning the matel thing in there. It's "too easy" to turn the knob, it doesn't "notch" into place like it did before. Broken off on the other side?
 
I pulled off the knob, and it isnt broken...it is turning the matel thing in there. It's "too easy" to turn the knob, it doesn't "notch" into place like it did before. Broken off on the other side?
To me it sounds like the Vacuum control mounted behind the HVAC control head. it would have a 3 or 4 electrical spade connector and a series of colored Vacuum lines plugged on to it. the detent section has probbably fallen apart. if thats whats broken, I've got one just laying around. Free but you pay for the shipping. Take a Picture of what you found so we know if i have the correct part for you. and for anybody who needs a Knob, i have 2 of them, also for free, you pay for the shipping. send me a P.M. to who ever is interested.
 

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Thats funny, the exact same thing happened to me last week on my 2000 Wrangler. Now I know what to look for. I don't think its the knob.
 

It must be a trend happenin'! a little over a week ago, my blower motor switch has been glitching on me. When you go from High to medium, you have to wiggle the knob around for the medium setting to come on. Could this be a loose connector or a dirty contact of some sort as mentioned?
 
It must be a trend happenin'! a little over a week ago, my blower motor switch has been glitching on me. When you go from High to medium, you have to wiggle the knob around for the medium setting to come on. Could this be a loose connector or a dirty contact of some sort as mentioned?
Yours sounds more like what Utah has covered on his post. Electrical failure rather than mechanical.
 
I pulled off the knob, and it isnt broken...it is turning the matel thing in there. It's "too easy" to turn the knob, it doesn't "notch" into place like it did before. Broken off on the other side?

On my 2001 the switch is hard mounted to the A/C board by a sturdy ring and soldered in. Since yours is a 99 there might be a slight difference, but I doubt that it is very much.
It only takes about 20 minutes to pull the center dash apart to see and less time to put it back together once you have done it.

When the YJ became the TJ starting in 96-97 ( yes folks there are some 1996 TJ's out there) DC started to change over the A/C control module from a part mechanical to full electrical. They completed the changes in 2001 then made a major change in design in 2003 to match the Rubicon model.

But the basic removal of the center beauty cover is the same through out all of the TJ's. The best advise is grab a phillips screw driver and check it out.
 

I have a "97 TJ" But looking at the orginal paper work it was bought from the dealer in October of 96.My heating control system does not look like the one in the pic.I think mine may be from a YJ.I only have a knob for the fan then levers for which vent and temp setting.My knob did break and I am having a hard time finding one in a junk yard.The newer TJ knobs dont fit.Time to stop at the dealership.
 
I'll try to get it taken apart...as soon as we get above 0 degrees wind chill anyway :) It's too cold to sit out there taking stuff apart, and we have a Subaru in the garage with a much bigger issue :p I appreciate the help! I'll post back with pictures when I get it apart
 
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