03' KJ with AC issue

[oblivionnewtonjohn]

Hi all, bought my coworkers 03' yesterday and the A/C isn't working, blows hot.
I looked around in the stickys to see if a common issue and how to troubleshoot.

I seem to recall on a forum some time back when I first started contemplating purchasing the KJ a common failure with the fan clutch?

New to Jeeps/MOPARS any advice is welcomed.

 

[HoosierJeeper]

Fan clutch wouldn't cause the AC to not work...maybe the AC clutch, but those usually fail pretty spectacularly, so I'd think you'd know if that was the issue. If it's low on refrigerant, it'll prevent the AC from running to protect it.

I'd get a set of AC manifold gauges and see what the pressures are. That can tell you a lot. But don't go adding in that stuff from an autopart store, it'll ensure you have to replace everything! This is one area where I think the $100 shop charge for a recharge and leak dye test is worth it.

 

[Aceofspades]

Can you see if the clutch is in engaging and disengaging first?
Mine was but hot air was due to the blend door motor being stuck.

 

[oblivionnewtonjohn]

Fan clutch wouldn't cause the AC to not work...maybe the AC clutch, but those usually fail pretty spectacularly, so I'd think you'd know if that was the issue. If it's low on refrigerant, it'll prevent the AC from running to protect it.

I'd get a set of AC manifold gauges and see what the pressures are. That can tell you a lot. But don't go adding in that stuff from an autopart store, it'll ensure you have to replace everything! This is one area where I think the $100 shop charge for a recharge and leak dye test is worth it.

Thanks for the reply, yes AC clutch is what I meant. AC work isn't my forte, I agree probably best to take to a shop for a leakdown.

I can do most other work, but have never attempted AC.

 

[oblivionnewtonjohn]

Can you see if the clutch is in engaging and disengaging first?
Mine was but hot air was due to the blend door motor being stuck.

That's exactly what mine is doing, hot air. I tried to circulate the outside which would should have been cooler, but it was straight hot air as if the heater was on.

 

[Aceofspades]

Well I would still visually check to see if the clutch is working. If not could be low pressure cut off aka leak and you have no refrigerant in the system.
Mine was cycling on/off , lines were sweating etc so next step was to dig into dashboard and fix the blend door motor.

 

[oblivionnewtonjohn]

Well I would still visually check to see if the clutch is working. If not could be low pressure cut off aka leak and you have no refrigerant in the system.
Mine was cycling on/off , lines were sweating etc so next step was to dig into dashboard and fix the blend door motor.

Agreed. Read over this thread http://www.jeepkj.com/forum/f202/how-replace-hvac-blend-door-actuator-59206/ after the mention of the blend actuator.

Mine blows hot either in AC or Vent mode, I mean heater hot like from the engine bay. Also notice when I changed the various vent settings, it sometimes does match up the first try or so, leading me to suspect the blend actuator but this thread says stuck in Cold position. Can it also hang in the Heat position?

Hopefully it's one or the other, not both.

 

[HoosierJeeper]

I would guess it could, probably breaks and gets stuck damn well wherever it wants.

 

[Aceofspades]

I made an access hole behind the radio hvac panel. Got it out and tinkered with it. Worked on the bench , put it back in and all is good for now

 

[oblivionnewtonjohn]

I made an access hole behind the radio hvac panel. Got it out and tinkered with it. Worked on the bench , put it back in and all is good for now

Did you document your access hole (sounds naughty :gr_grin with pictures?

 

[oblivionnewtonjohn]

Found this thread while documenting steps, KK has the actuator in a different location (lucky) but I have the same blows hot symptom. As stated above, it appears possible it can also break/hang in the HOT position though most threads mention COLD. http://www.lostjeeps.com/forum/phpBB3/viewtopic.php?f=88&t=72544

Does anyone have a copy of the 2003/KJ HVAC manual? I hate to get the dash apart and not have all the parts on hand to repair once.

 

[Aceofspades]

Did you document your access hole (sounds naughty :gr_grin with pictures?

Lmao no but it "wasn't pretty"
It can be done and you will have a hard time- but not as hard as removing the entire dashboard

 

[oblivionnewtonjohn]

Lmao no but it "wasn't pretty"
It can be done and you will have a hard time- but not as hard as removing the entire dashboard

Oh the joy! My last daily had a bad heater core, same deal, whole dash to repair but some guy found a similar fix as you mention. I guess I will block off a weekend soon, because it's killing my MPG further riding with the windows down, and it's still hot here in Nashville.

So far I have this repair and the rear windows to do. I sure hope once I replace the blend actuator the A/C actually works, if the cosmos could at least throw me that bone....

EDIT: found the HVAC section in my FSM Chapter 24.

Is this similar to what you did to replace? Do you patch the hole when completed?
https://www.youtube.com/watch?v=xf22fvcN1hU

 

[oblivionnewtonjohn]

I did the manual blend door calibration (3 times), I cannot confirm my previous findings with certainty, but the A/C works, but in reverse (temp set to HOT) which I've seen mentioned in some of the threads I've came across.

I'll need to dig further but I'm happy I at least have air for now!