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Grand Cherokee AC air door issue

I own a 1994 Grand Cherokee and the AC air mixture door sticks sometimes and will mix hot and cold air for a few moments, then I hear a light thump and the door closes and cold air comes out the vents.

I think the linkage that controls the door is sticking and it is dirty with debris around the linkage. Where is the linkage control located on the Grand Cherokee and what does it look like ? The underside where the floor vents is where the door is located, but I cannot se the linage like I could on older autos.

I see a small bell shaped cylinder with a line going into it, but I'm not sure what is is. The part in under the drivers side near the center where vents branch out from main duct. Any help would be appreciated. Thanks.

WB

Reply to
WildBill66
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WildBill66 did pass the time by typing:

Sometimes the sealing foam tape they use comes loose and gets in the way of the door, or the vac motor gets obstructed either by dirt or by a wire bundle coming loose and resting on it. But more often than not it's a vac leak on the engine side.

Like all things ZJ, they are hard to get at.

That's the heat/defrost door actuator

Here are the rest.

Recirc door air actuator. This pain in the butt is located above the blower motor on the firewall side of the HVAC unit.

Panel/defrost actuator. Drivers side of the HVAC unit about in line with the VIC. Not sure But I think you can get to it by taking the VIC out. It's been a while.

You might have a slight vacuum leak and it's taking that long for the vac to build up and finish moving the door.

As old as your ZJ is, I'd be checking all the vac lines under the hood.

Reply to
DougW

Doug,

I'll start with the vacuum leak check since its the least painfull back breaking checks.

I replaced the AC blower fan in November, I should have pulled the seat out, would have been easier with more room in the floor area. So if no leaks are found. Do I pull the blower motor or do I have to pull the glove box to reach the Recirc door air actuator ? Is the linkage visable or do I have to fell around to find it by hand ? Thanks.

WB

Reply to
WildBill66

WildBill66 did pass the time by typing:

Unfortuantly you can't get to it through the top since the relay tray hides under the glove box. It's a reach around the back/side and is a real pain in the butt as there is very little space. I think the big service book states to remove the whole assembly for service. That's nuts since it means discharging the AC system.

I service what I can reach and live with the rest. :/

As for breaking your back working under the dash, try this. Get a piece of 1/2" plywood about 1' wide and 3' long. Sit it on the door sill then lay down on top of it. that gives your back a rest.

Reply to
DougW

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