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Jeep Grand Cherokee A/C Heating Ventilation



  • crumbiecrumbie Posts: 1
    This is for a 2002 Jeep Grand Cherokee with the v6, 4.0l engine.

    Currently, when we turn on the a/c, sometimes we get cold air and sometimes it's warm. And it's always hit or miss, sometimes cold, sometimes warm. Switches back and forth while driving down the road.

    We also noticed during the winter, that most of the time there was heat, but other times the air would come out cold.

    Does this sound more like a blend door type problem or a blockage in the cooling system? I know there has been pages and pages of discussion, but I just wanted to throw my specific problem out there to get help.
  • pahefner01pahefner01 Posts: 202
    It is quite possible that the only problem is the "shims" in your ac clutch. I had this happen with my Cherokee. I went to AutoZone and bought a compressor and rented some tools. I found when I removed the front part of the clutch, cleaned it up and removed on little thin "shim" and the ac was fine. No dealers. The shims are actually little washers.
  • blendorblendor Posts: 23
    I don’t know if you have checked the AZC (Automatic Zone Control) fault codes before you started to do the repairs.
    The Blen Dor Store on Ebay has a description of how to read the fault codes of the AZC systems. And will explain which fault codes you should be getting for a blend door and an actuator motor failure. The wjjeeps web site has a list of all the AZC fault codes. The Blen Dor Store also has a short description on how to check for a blend door failure for the MTC (Manual Temperature Control) systems.
  • blendorblendor Posts: 23
    It could be the blend air doors are broke and bouncing around causing the doors to stick in various positions. But you would probably have to be bouncing that Jeep around pretty good to get the doors to bounce up and stick in such away to block off the AC.
    It is most likely a blockage or an air pocket or actually it could be a number of things.
    But the best place to start is by reading the AZC fault codes. There is also a wjjeeps web site that will have the complete AZC heater fault codes. If you would like to check the blend doors you could go to the Blen Dor Store on Ebay. There is a small description on how to read the AZC fault codes to match the broken blend doors and faulty actuator motors and how to check manually if your blend doors or actuator motor have failed.
  • funpigfunpig Posts: 3
    Re: Message 231 above.

    I also suggest try removing one of the shims or washers from the clutch assembly to get it to work.

    I have a 94 grand cherokee. Recently, I developed a problem with the clutch on my ac compressor. It was cycling on and off and sometimes not working at all. When it stopped working, I could get it work again for a while by giving the clutch a tap or hit with a rubber mallet.

    One issue is low coolant. I have a small leak that neither dealer or mechanic have been able to locate in the last five years. Fortunately, the leak is so small, I just need to top up the coolant just once a year.

    My mechanic said that the clutch on my compressor was worn. Great guy. He said normally shops will just recommend replacing the whole compressor (very expensive). He said that what happens is that the clutch gets worn and dirty over time and the gap between the clutch and the other plate gets too big and the clutch slips when it tries to engage electromagnetically.

    This is what he did. He undid the bolt on the front of the clutch assembly. He needed a large wrench or pliers (about a 4 inches) to grip the clutch so that it would not spin while he undid the bolt. Then he used two screwdrivers to lever the clutch away from the compressor. The clutch is mounted on a splined axle. He used compressed air to blow out the dust and gave it squirt of WD40 just for luck. Inside the hole of the clutch (this is the hole where you insert the splined axel) are several shims or washers which set the gap between the clutch and pressure plate. He removed one of the washers using a small magnet and the he reassembled everything. By removing the washer, the gap between the clutch and the pressure plate is now smaller. The clutch stopped slipping.

    Everything seems to be working fine (for now). The gap may be a little bit too small because I notice some occassional minor rubbing sounds inside the clutch when the clutch is not engaged. I'm going to check back with the mechanic, but I think that over time, it should just wear down naturally.

    If your clutch is malfunctioning, this is worth a shot especially if your option is to replace the whole compressor anyways. Be careful that you don't break or warp the clutch when you try to remove it. Also, if you make the gap too small (take out the skinniest washer or just replace a thick one with a thinner one), you may get some major rubbing or even have the clutch seize up on you.

    14 years, 215,000 km. Had to get tranny and rear diff rebuilt last year. SUV has almost no value with the price of gas these days. I still enjoy driving it, but I cannot live without ac. If the ac completely goes, I'm going to get rid of it.

    Good luck
  • Have 96 GCLimited. A/C worked great until about 2 years ago. Have now spent around $1500 at dealer trying to get permanent fix to huge leak which shows up on passenger side floorboard. Also notice trash (leaves, twigs etc.) in the vents. Any ideas?
  • funpigfunpig Posts: 3
    I have a 94 Laredo. Since new I have always had problems with the AC. The defective evaporator core was replaced about 8 years ago by the dealer. Over the last 5 years, I still suffered from a small leak. I recharged in June and it would slowly leak down and the cooling would deteriorate until it was gone by about September.

    I live in Canada. We cannot buy the little cans of R134 like in the US. Each time I would need to go to a shop and spend about $100 -$150 for a recharge. Neither dealer nor shop can locate the leak using dye. They can only guess that it is probably the evaporator again (about a $1,000 repair). I suspect it is some small leak in a seal. Anyways, I decided to take a chance on Duracool which you can buy at an auto parts store or Walmart here in Canada. The stuff is flammable and is not permitted in some states so this is the risk that you have to take if you decide to use this stuff. Also, it will void any warranty on a new vehicle. My rationale for using it is that Duracool is readily available and cheap in Canada and it has a molecule that is about 2.5 times bigger than R134 which is less likely to leak out. Also, it is not poisonous nor corrosive, unlike R134. My 94 grand cherokee is too old to be spending big bucks on a proper fix, which may or may not work.

    Other than the leak, my AC cooled reasonably well when it is fully charged. (The compressor clutch was slipping but it was fixed, see message # 234 above). The oil is clean (Duracool has a little filter indicator to visually test the oil quality). I got my mechanic to evacuate the remaining R134 out of my system (it is illegal to mix refrigerants). He then pulled a vacuum of 29in Hg for 30 minutes to make sure the system was fully evacuated of any moisture. I then charged the system using duracool following the instructions. There is a toll free number which I called to make sure I was doing everything right. The key is not to overcharge. A slight undercharge is okay. Just put in the first can and take it slow from there. Give the refirgerant a chance to mix with the existing oil in the system. I found that the AC did not initially work well until about 15 minutes of running it.

    The results have excellent so far. It is cooling much better than before with the R134. After several weeks, the pressure on the low side was still the same (38psi) and I have not noticed any fall off in the cooling so far. Also, Duracool has a stench so that you can detect any leaking gas and I was happy to discover that there is no leak or smell from the evaporator, so it turns out that I did not need to replace the evaporator core (saved $1,000). YMMV.
  • wschillerwschiller Posts: 2
    Hi Kodysgrandma1:

    I have the same problem with a 98 Jeep GC. The problem is the evaporator drain line is plugged with rotted leave matter and such. I can not find the drain hose or evaporator outlet where it penetrates the firewall. This leads me to believe that we are dealing with a double panel situation and the a/c evaporator drains between them to the ground.

    I managed to clear my line for about a day by removing the blower motor and snaking a small rubber tube down into the evaporator drain area. It worked fine for about two days then it plugged up again because of stuff that has accumulated in the evaporator housing.

    You will notice that the condensate water is coming out of your floor vent in front of the counsul. Also, because the drain line is plugged, condensate forms on the outside of the a/c plenum unit under the glove box and drips down into the passanger side footwell.

    I have talked to several shops about this problem and they all had the same answer: Remove the entire A/C unit from under the instrument panel, disassemble it, clean it and re-install it. This entails allot of work including removing the entire instrument panel, etc. This is not the answer that I was looking for so I intend to drill a hole in the evaporator drain area, drain it, try to clear it with a wire or compressed air and re-seal it. If it works, I will post it.

    Good Luck,

  • Thanks wsciller. That's what we have paid for 3 times so far and I really didn't want to do it again. Another dealer give me the "well we don't know how well it was done" story when asking why it wasn't a permanent cure. Says if you park under trees the wind will force the trash down. Now if trash wasn't forced down for the first 8 years why don't I get 8 again after it's "fixed"? Hmmm What broke to allow the trash down there, why isn't there a better fix etc. etc.? If your idea works perhpas we can find someone to try it for us. At 70 we're not about to- husband has heart and diabetes problems, I have artificial hip and 2 artificial knees. Crawing under cars sort of out of the question.
  • funpigfunpig Posts: 3
    Water condenses on the cold evaporator in your dash. The water is supposed to drain away. When it is draining properly you should see water dripping underneath your vehicle just inside and behind the right tire. Over time, there is a build up of crud and the drainage gets blocked.

    Go to or There is a detailed explanation for fixing the problem with diagrams or pictures. If you pull back the top of the passenger carpet, you can see a black plastic drain. You need to drill a small 1/4" hole and stick a coat hanger in there to clean out the crud. Then you need to seal up the hole with a plug.
  • I have the carpet pulled back most of the way right now to dry it out. Have not seen the drain but maybe need to go a little farther back with the carpet. Will look in the morning and also at the web sites. Many thanks.
  • wschillerwschiller Posts: 2

    I have a 1998 with the same problem. The drain exit port is not visable on the engine side of of the firewall because it terminates behind a frame gusset. If you look at the A/C unit under the dashboard, you will see how the A/C enclosure slopes down and towards the inside of the firewall. This is under the the Evaporator Housing. Coming down from the sloping housing you will see a 1-1/2" is wide black plastic duct that terminates in a flat circular shape. This is the drain exit port through the firewall. I drilled a 1/8" hole in the center of the circular shape after which I was able to clear the blockage with a 1/8" piece of electrical wire. I then resealed the hole with a machine screw.

    Good Luck.

  • compressor will engage in defrost mode.but will not engage in normal a/c mode. Any ideas ??
  • tuggajbtuggajb Posts: 646
    ac on off button switch probb bad
  • 95zjtom95zjtom Posts: 8
    We had this problem on my wife's 95 GCLtd about six or seven years ago. I took it to a Jeep dealer and they found a technical service bulletin that told them the drainage area gets clogged with leaf and other organic debri. The tsb said to drive a 1/4 or so hole in the plastic air conditioning box just above the passengers feet. This box is rounded and the hole should be drilled about in the middle. Have a coffee can or something ready as you most likely will see water pouring out once the hole is made. After the water stops running out. take a can of compressed air or an air blaster tip attached to an air compressor and blow air into the hole. This will blast out the debri that has collected in that compartment from the engine cowling area. If you get the hole in the middle, you can actually poke a wire or thin wood dowel all the way through the other side. When you think you have the debri cleaned out, plug the hole with one of the plastic plugs that are used to hold plastic body parts on. Seal around the plug with silcone gasket cement.

    I have done this same thing on my 95 GCLtd with success also. I have since installed drain tubes on both Jeeps so I don't have to go back each year and clean out the air conditioning box. If you want details on how to do this let me know.
  • I for one, would greatly appreciate any details. Our 95 GCL has been in the shop 3 or 4 times over 3 years to the tune of about $1500 and still no permanent fix. We do have a mechanically minded friend who could do this for us though if we had the specifics. Many thanks
  • jaf6jaf6 Posts: 1
    I have a 2001 grand cherokee loredo and no matter what i turn the controls to it only blows out the defroster any ideas thanks.
  • Sparry
    I have an 04 GC with the same problem. Under warrenty the dealer replaces condensor, evaporator and who knows what else. A/C worked for awhile and quit again.
    How did you fix yours. Thanks Steve
  • I have a 96 Grand Cherokee Laredo with the v8 and the other day we discovered a leak in the passenger floor boards and discovered that the a/c is not leaking the condensation off under the jeep like it normally would except it is coming in the floor some where I did what every body has said to do including the a/c shop in town by drilling a small hole in the duct work down under the dash so we did and nothing happend we noticed later it leaked outside the jeep like it should thought we had it fixed but no i was wrong it is still coming inside what do you recomend????
  • blendorblendor Posts: 23
    There are a few things that could be the problem.
    1. The mode control switch could have failed at the defroster position.
    2. The mode door actuator motor has failed.
    3. The mode door could be broken.
    4. The defrost door actuator motor has failed in the open position causing most of the air flow to be directed to the defroster vents.
    5. The defrost door could be broken.
  • 95zjtom95zjtom Posts: 8
    Sorry about the delay in replying to your request for more information on how I fixed the irritating air conditioning condensate water flooding the right side floor on both of our 95 Grand Cherokee Limiteds. We first noticed this problem with my wife's GCLtd about seven years ago but the water came out the air vent to the right side passenger's floor. On my 95 GCLtd the water came out onto the front passenger floor.

    My remedy is first to obtain the "plumbing" parts listed below. I bought these at the Home Depot but any good hardware/home supply will have what is needed. I will include pictures which should help illustrate the fix.

    One plastic elbow with a hose connector (hose barb) on one end and threads on
    the other side. One plastic elbow with a hose connectors (hose barb) on both ends. Approximately one foot of plastic tubing. One the Jeep illustrated I used clear tubing but on my wife's Jeep I used black reinforced (as in fuel line) tubing.
    The important thing is to puchase the correct size tubing to fit the hose connector end of both elbows. As for the threaded end of elbow used at the air conditioning duct - you will need a thread tap of the correct size. You should also have availalbe some RTV silcone gasket cement or another brand of silcone sealer (as in 3M).

    For installation, drill the correct size hole in the center of the round water collection point in the air conditioning duct and use the thread tap to cut threads for the elbow. Drill a second hole in the floor just large enough to insert the one end of the second elbow. I drilled it in the flatter floor area and just through the first layer of sheet metal. This hole will let the water drain out onto the ground from this new location.

    Screw the threaded end of the first elbow into the hole you created in the ductwork. Push one end of the tubing onto the hose barb end of this elbow and the other end onto the hose barb end of the second elbow. Insert the other end of this elbow into the hole drilled into the floor. I then used the silicone sealer around the elbow threads in the air conditioning ductwork. There is no pressure so if you got good thread cut into the ductwork you may not need the silicone sealer. I had some on hand so I sealed it up (see the blue stuff I smeared around the elbow).

    As I mentioned, this fix is working great for us and I no longer have to clear out the hole in the firewall of the debris. As was mentioned by some posts, it does help if you do not have to park under trees. I have used a hose to flush out some of the debris but holding the end of the water hose over the cowling and letting it flow. I have also sprayed a hard stream of water into the holes in the firewall behind both front tires. I do agree that Chrysler/Jeep did not get the design right so the debris will flush out by itself but are other manufacturers better in this design?

    <img src="c:\acfix1.jpg"

    <img src="c:\acfix2.jpg"
  • tidestertidester Posts: 10,059
    The pictures you tried to post don't show up because, fortunately, we aren't able to read files directly off of your computer! :)

    The easiest way to post pictures is to place them in your own personal carspace and link to them here. You can find your carspace by typing "" followed by your username (no quotes!) into your browser's address bar.

    tidester, host
    SUVs and Smart Shopper
  • 95zjtom95zjtom Posts: 8
    I thought I was including the pictures correctly - but I was not.. The pictures showed up when I previewed my post but I have since been enlightened. I neeed to upload the pictures to my CarSpace. I have done that and I will attempt to add the pictures to this reply. .html#pic .html#pic
  • 95zjtom95zjtom Posts: 8
    Thanks - that makes sense why the preview showed the pictures. I had my wife this morning get on the forum as a guest to verify the pictures did not show up.

    Since then I added pictures to my CarSpace album and created a reply the post I made last night with the url for each picture. This should work better.

  • awiggieawiggie Posts: 1
    Hi. I have an 05' Grand Cherokee and am having issues with the blower settings working for my heat and a/c. I called the dealer and was told that it was the blower motor resistor. Replaced it last Tuesday and was working great and now only when it wants to on all settings and only on hi all of the time. Not sure if I should replace the part again, maybe defective??, cheap part only $5.00 but a pain to put in. Any info and/or advice would be a great help. Thank you! :)
  • gwd601gwd601 Posts: 8
    I'm about to "do battle" w/ my 01 GCL regarding stuck blend doors. Same problems as others have experianced, heat on drivers side and cold on the passenger side, except when the blend door behind the glove box sticks or slips or whatever they do, then there is no heat at all except insde the box it'self. Anyone have any suggestions besides removing the entire plentum box and replaceing all of the componets?
  • gwd601gwd601 Posts: 8
    I have an 01 GC limited and have been into the driver's heated seat problem. I learned from the dealer that the correct way is to replace the leather covering of the seat because the elements are sown in when it is made. $1200 plus labor. I took my seat aprt and found the bad element and cut it out of the circuit (by-passed) That was a year ago. So far so good! gwd601
  • tuggajbtuggajb Posts: 646
    look on ebay for jeep blend doors repair some one has a kit with instructions cost bout 150 or so
  • gwd601gwd601 Posts: 8
  • I have a 2000 Limited 4x4 (Quadratrac). My issue is the heat works fine for about an hour but then blows cool/cold air after that. Any suggestions?

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