Climate controls problems(intermittent)

Ok, I tried searching but it's hard searching for short terms like AC unless I am missing what modifiers to use?

My Ac hasn't been used for a few years, recently I replaced the compressor/drier and had it vacuumed and charge. We let it run for like 40 minutes and it was blowing ice cold no problems. I drove home and ran it for another 40 minutes no problems. I tried to turn it off and right back on, it didn't come back on first try, it took a few tries then it came on and was fine. Today I go to use it and nothing again, turn the knob back and forth eventually it kicks on and it's fine. It is the same with all setting, turn the knob get nothing at all, then suddenly it works strong. It doesn't seem like the compressor is running just not the blower, it seems like Nothing is turning on. I need to go check it out furthor but it's like 100* in my garage right now figured I'd ask first get the ball rolling...

I am guessing it is the switch but I can hear some sound coming from the vent. If you turn the ac on with the car Off it makes a sorta vacuum sound behind the middle vents, I get that sound when I try my ac while driving.

I checked the fuses they were a bit cruddy but nothing stood out, cleaned them all and haven't checked for improvement yet. I'm thinking the switch maybe is just acting up since it's All the climate settings? Could it be a vacuum leak? I figured if it was a vacuum problem the blower would still function?

97 country

i would explore a vacuum leak.

im not familair with how your controlswork, but have you tried turning the blower on by turning on the heat or vents. trying to rule out if its a blower issue, as it seems more like a switch control or vacuum issue.

89xj said:

i would explore a vacuum leak.

im not familair with how your controlswork, but have you tried turning the blower on by turning on the heat or vents. trying to rule out if its a blower issue, as it seems more like a switch control or vacuum issue.

Click to expand...

Yes, the same thing happens when I turn climate knob to heat or vent or whatever. No combination seems to trigger any reaction, just randomly it works on whatever setting I turn it to.

I guess I should note while thinking more of vacuum leak. My idle has been slightly ruff, nothing you would really notice. I have a small crack in my exhaust and blamed my idle on that. Maybe the vacuum leak has gotten a bit worse and causing this new issue along with my idle issue...

I have a vacuum gauge test kit, is there a good spot to tap into and test for leaks off hand?

just about any vacuum hose coming off the intake manifold that fits the connection on the vacuum tester/gauge.

also look and listen for leaks. check all vacuum connections. trace vacuum lines that run under the battery(common leak area) to the vacuum ball in the passenger side front bumper.


if you test vacuum and find its not holding steady or its low but cant find the leak, can use an un-lit propane torch tofind the leak. idle will increase if you direct/spray the propane to a vacuum leak.

does your cruise control work. i wonder if its an issue with the blend door?

Ok I just went out and messed with it a little bit.

The compressor is engaging properly as well as the eFan and my refrigerant is at the correct levels. Still no setting blows air though, I can hear the blend doors moving when going from heat to Ac. Playing with it for a good 10 minutes I never once got it to function though.

I dug up an old thread referring to the blower motor relay or resistor behind the glove box. I might start there as everything seems to function except the blower control at this point. When the blower has kicked on I could adjust the speed and it remains steady and strong before it suddenly cuts out.

Or, could the symptoms still point to a vacuum problem? I will check the vacuum anyways I guess might as well since I have the gauge. I honestly haven't used the cruise control in forever, I will try that next time I drive though.

does your fan work for heat on any settings? Maybe just on high. It usually takes a few seconds for the vacuum switches to actuate. Under the glove box there is a cover for the ac vacuum switch thing. Pull the cover and you should also find the blower resistor. Grab a test light and pull the wires off the resistor. Key on and run through the fan settings while probing the harness. light should come on for each different setting. No light ,then you have to crack open the dash. Odds are the fan switch fried some wires since you aren't getting any air. I have seen a few melted harnesses from a short in the fan switch.

Blower fan doesn't work on any settings(speed settings or climate settings).

I just checked for vacuum leaks and found none. I tapped into the vacuum line near the cruise control and let it idle and pulled a steady 15 on the gauge. Turned the jeep off let it sit with the gauge and it held dead on 15. For kicks I pulled the end cap and checked the vacuum reservoir, no leaks found. After the jeep was off and the vacuum released, I noticed there's no longer the vacuum sound from behind the center ac vents. All of which I assume are good signs my vacuum is not the cause of my problem.

I pulled the center console and checked the climate control switch, it looked fine. No sign of melting in or around the actual switch, I had my stock fog lights melt the switch so I was kinda expecting to see something. I didn't trace the wires very far but nothing jumped out at me.

I guess next I will get the test light and start checking what jodaddy recommends. If the problem is in the wiring between the switch and the resistor is dash removal the only? :explosion Or, can you wiggle the harness out from under the dash enough to work with? I thought I saw a harness running along the floor just at the edge of the dash that looked like it would be the one I need.

check the harness at the resistor first since it is only 2 screws to get to. No power there then pull the dash trim.

Just to update my findings(maybe fix as well).

The past few days I've been trying the blower on all settings and have gotten Nothing at all during any conditions.

After I searched some more and read up on the blower location and everything I went out for a quick check. I pulled the blower plug under the hood and checked continuity. With the ignition off I got nothing with the ignition on and ac on I got good continuity. I decide the harness/switch side of things are good to go.

Then I thought about hooking power directly to the blower but it's such a tight spot and the risk of touching my power leads seemed too dangerous :explosion . I also thought about whacking it with a hammer to see if that was the fix(well to indicate bad brushes) but decided to hold off on that for now as well.

I sprayed the plug with some contact cleaner and plugged it back in nice and snug and checked for function. The blower works perfectly! I am hoping now that the connector came loose that caused my intermittent problem that turned into an absolute problem as it came fully disconnected.

I kind of regret before pulling the plug out I didn't try to push it in first to see if it had come loose. It was in such a tight spot that I doubt I would have noticed though. I want to pull the plug again this weekend and put some dialect grease on it and make sure it's fully seated. I'm not sure if my new poly motor mounts vibrated it loose, if I dislodged it when replacing the drier(I don't think I was near it but who knows) or if it was a combination of age and the above.

Thanks again for every one pointing me in the right directions.