06 LJ HVAC Stuck Defrost Door

[dtroth91]

Hey all,

Having an issue with my HVAC that I strongly suspect is the defrost door being stuck by interior debris.

A few years ago my driver door glass shattered and sent glass everywhere including up on the dash area and I specifically remember at least a few prices of glass falling down that I just figured will always be apart of hvac system ha.

I replaced vacuum lines, initially thinking it was a vacuum leak. Interestingly though, I've read that this usually defaults the system to defrost mode for safety reasons. My hvac was stuck on face only, and I could adjust the feet door well enough. I felt vacuum in all areas necessary, albeit weak, so I replaced some of the lines in the engine bay and replaced the section going from the "T" into the glove box.

This did have an improvement (I am pretty sure at least) in the vaccuum I was feeling, but it still wouldn't move that defrost door.

I pulled the actuator off and seems to function fine as far as I can tell.

I reached and really gave it some strength to try and turn this panel door manually with little luck. It moved a little but I heard cracking. I suspected this was the plastic breaking so I did not try to push it anymore.

I was able to free it enough that it will sort of cycle partially, and I can get SOME air to come out the defrost by cycling through the settings on the hvac switch (fairly new switch)

We have an 02 tj at work that I was missing with and those doors seem like they turn much easier in this vehicle.

I dont hear any hissing from any vaccuum lines and I feel vacuum at all hoses. I don't think this is a definitive test, but after feeling how hard it was to manually turn the door, I am fairly sure it is obstructed.


I tried to get in their with about 24" of flexible vacuum hose and it didn't seem to pick anything up.

Has anybody ever disassembled their dash, to cut and access this door area to clear it out? I've heard people use compressed air with some luck, but given that I suspect glass is obstructing, I'm not sure thisnwould be powerful enough to blow this debris out.

If anybody has cut into their hvac or has had a similar experience, it would be great to see some pictures of where you cut into it or what you did to fix it.

Thanks

 

[dtroth91]

I tried manually turning the defrost door on the tj at work and confirm something is absolutely obstructing my door.

It looks like I could maybe cut a small access hole near where the actuators are and patch it afterwards.

If I give this a try I'll update the post.

 

[Bigfoot-NM]

Interested in your findings. I have an 06 and it is stuck on the dash vents with a little coming out the foot well. I’ve been through the same process as you and came to the same conclusion that something is blocking the movement of the door.

 

[CharlesHS]

There is a good chance that the door movement is being blocked with a couple larger chunks of glass as you suspect. I would suggest you be careful when cutting a hole and thoroughly examine where the heater core and evaporator coil are located so you don’t damage them. You can use a small circular hole saw for access once the areas of the heater and evaporator are confirmed.

 

[macleanflood]

Personally I'd pull the HVAC box much like you'd do to replace the heater core.

It's a pain but it's manageable. And it's really the only way you'll know if you got every piece.

-Mac

 

[dtroth91]

I'm getting enough defroster air that I'm not really interested in pulling the dash to fix this.. yet.

Since my actuator/door is stuck in "up" position, I was thinking I could disconnect the actuator, and drill a small hole with a circular saw as recommended roughly where the actuator arm would be in the "down" position.

My use of the terms are up and down are relative to the position of the actuator/arm, not necessarily the doors actual position on the interior of the hvac.

This would be roughly where I marked in blue. The actuator is in what I would call the "down" position here, as this is the wrangler we have at work.

Based on this diagram, I should be well clear of anything I want to avoid right?

I would still take great care when making the hole however.

Then I could position some compressed air to blast more directly at the door to break some stuff free.

 

[dtroth91]

Interested in your findings. I have an 06 and it is stuck on the dash vents with a little coming out the foot well. I’ve been through the same process as you and came to the same conclusion that something is blocking the movement of the door

I'll let you know when i tackle this.

I actually found a wet passenger floor so I may end up completely dis assembling the dash.

I'll report whatever i find either way

 

[Artsifrtsi]

I would not compromise the integrity of HVAC box. The only issue that you will encounter, is you'll need to get the AC evacuated and recharged.

Do it the right way... doing it the shortcut way turns you into the next DSPO. Remember the phrase... "Don't start vast projects with half vast ideas..."