2002 hvac issues

rbaucom7266

New member
I have a 2002 tj and the selections that will work is defrost and floor defrost. they will change between the two but that's it. History tells me that its a vacuum leak. I replaced the vacuum line from the reservoir to the firewall then to the intake. With out putting a gauge on it, I am going to assume that its cool. Can that reservoir go bad and need to be replaced??? Other than Im going to say that everything is good to the selector switch. (tidbit here, with the jeep off I can turn that selector switch and here some air movement coming from it,Ii guess till the reservoir is drained) With the jeep on i can turn the switch and I don't see any of the actuators arms moving. So again I am going back to vacuum leak. I know the yellow and blue lines are the floor and the red and brown are the dash vents. The arm on the dash vent actuator is disconnected but i would think it would still try to engage when put on that setting, it doesn't!!! I found one more actuator behind the glove box it only has a green vacuum line going to it. I don't really know what that one is all about. (only one vacuum line, maybe side vents or side defrost, not sure. I found the blend door and I cant tell if its working or not. I turn the knob but i really don't hear it moving with the car ignition switch turned on. I know i need to replace the dash vent actuator or find something to connect the arm back to the door, but the actuator should still function. The blower fan is running fine and I hear it changing speed and the defrost is spitting out good heat. So what am i missing???? Should I just replace the selector switch. With out vacuum gauges i don't know if it's even working right. I have never used a vacuum gauge. If i get one how do i use it and what should it be reading. The jeep just got a paint job in a dusty shop. Could the dust, messed the switch up. Read a ton of stuff on this but not a lot of stuff on the newer tj"s Any info or suggestion would be super awesome, Im super serial!!! Since turn the selector doesn't activate the actuators, I'm going to still say bad selector switch or a vacuum leak somewhere, but i have been wrong before, a lot!!!!!!!
 

Yes

Sorry the app keeps closing on my phone so all I get to type is two to three letters.


Vac leaks are the cause. Well insufficient vac. Besides the line from the intake to the firewall then to the resivor, there other possible sources. Any vac leak at the intake or any other vac line contributes to the issue. What does the engine idle at? Should be 750 rpm. If more 1000 or higher you still have a leak. You could find the sources by idling the engine and take WD40 or carb cleaner... And spray around the vac lines, intake and intake to cylinder locations. Do this slowly and listen for a change in the idle.

Beyond this the lines inside can leak resulting in a similar issue.
 
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I drove my jeep the other night. While I was driving it I was turning the vacuum switch and it was switched from floor to defrost but not dash panel (which I know because the actuator arm was broke)!! When I got home I looked under the dash and turned the switch and I saw the actuators were all moving. Hooray I have vacuum. So last night I fixed the actuator arm and started turn the switch but nothing but defrost. Booooo. Then it dawned on me and I might be totally dumb. Am I draining the reservoir by doing all this trouble shooting with just the ignition switch on??? Do I need to have the jeep running for the vacuum to work. The jeep does idle at 1000 by the way. How a vacuum gauge work. Could I use that????
 

I feel so stupid!!! Well I got my heat and air working. It was the broken actuator the whole time. I was just trying to trouble shoot with just the ignition switch on. I finally realized it tonight and fired her up and she works like a champ. So I guess if you cut your A/C or heat on with the car off it will just blow defrost or what ever selection the actuator in at the time???? For future reference have jeep on when working on vacuum lines. DUH!!!!!
Thanks guys!!!!!
 
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