HVAC vent problems

KKomodo · **Posted:** Tue Oct 01, 2013 10:36 pm

I just recently starting having problems with my vent doors. My blower motor works and I have ac and heat but it will only blow on the floor or defrost. I get some out of the dash but it won't go full or partial dash/feet at all. Can hear it change from floor to defrost but thats it.Should I start looking into new bulk head switches or is there a way to test the vent doors?

Scar0 · **Posted:** Fri Oct 04, 2013 4:56 am

Lay on your back drivers side seat, looking up at the HVAC system. You will see the actuator motor. attached to it is a white arm which controls the door position. While under there, change the mode to different positions. the motor should turn and the white arm should move.
There is a large write up on this issue on the nitro Z forum.
Search my username Scar0 and "Mode door actuator". It is titled "No heat to the floor and no defrost". In his case the issue was reversed, but the mode doors control which direction the air flows.
Use caution, there are some things written there which could cause damage to your rig if not done correctly. I'm not responsible for how you use the info posted. Do it at your own risk.
It could be as simple as a stuck door. Which I believe it was in his case.
Ah, heck here is a link. If it's not OK Mods please remove it...

tommudd · **Posted:** Fri Oct 04, 2013 6:06 am

No problem ScarO
good information, great write up :wink:

Scar0 · **Posted:** Fri Oct 04, 2013 6:09 am

Thank you. Cool deal on the link. They are more strict over there. Can't link back to here... Too bad really, there is some great info here.

KKomodo · **Posted:** Sat Oct 05, 2013 7:26 pm

Well looks like I may of lucked out. Looked up under there and could see the actuator moving. But the rod looks like it fell out of its tab or something. I can see the rod then a tab piece like it should fit in a slot. I don't have any torq bits with me at home to remove it so ill have to grab some from work tomorrow

Scar0 · **Posted:** Sun Oct 06, 2013 10:21 pm

Hope that all it is. Let us know what you find out.

KKomodo · **Posted:** Mon Oct 07, 2013 11:31 am

Well got the panel off yesturday and got everything back into place and it does work again. It doesn't seem to switch all the way back to the upper vents but it does switch now. Guessing ether there is something stuck or the plastic parts are junk. For now its good enough. Ill wait to see if it pops loose or need to gears down the road

Scar0 · **Posted:** Mon Oct 07, 2013 12:32 pm

Glad it is working again.
Sounds like it may have become maladjusted and needs to be calibrated again.
Unfortunately that is a dealer thing...

DrDavis · **Joined:** Thu May 07, 2015 6:38 pm **Posts:** 2

So I've had the same problem with it stuck on defrost.

So I followed the instructions and got to where the mode door changes. I'm assuming there's something blocking the door because I couldn't move it freely by hand and the gear looks to have jumped out of the rail. I attempted to put everything back and I think I left something different because now the air conditioning is stuck on "feet" instead of defrost. Since the door is stuck the gear just pops out when the motor attempts to change it.

Looks like I'll need to get this fixed sometime this summer

So is my only bet, going to the dealer? Is taking apart the dash the only way to get in there? What is something like this going to cost me if I have to take it in?

Scar0 · **Posted:** Tue May 12, 2015 1:25 am

If it is just the mode door actuator the cost is not much. If the door itself is stuck the HVAC system has to be removed. Including the dash and A/C system. That will cost a bunch of $$$.
One KA owner was able to get into the blend door area through the center vents. See post 9 in the linked thread above.

HVAC vent problems

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