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Jeep Grand Cherokee A/C Heating Ventilation



  • bradyrbradyr Posts: 4
    edited September 2010
    Good morning all,
    I have a quick question regarding the blower motor resistor. I have had all the problems with the vent doors, actuator motors and all other crap parts jeep puts on their vehicles....I complained to chrysler due to my dash haveing to be removed 4 times for the vent problems and chrysler paid for my final repairs minus the 100 deductible---just a suggestion to everyone else on chrysler and to my current problem...yes my blower motor resister connection melted creating a bad connection for the black wire port in turn creating my newly installed vent system to not operate...i tred removing the resister but due to melted plastic I cant seem to disconnect the if any way possible can i cut the plastic or disconnect the resistor motor from its connection so I can clean or cut the melted plastic to create a solid connection to the black wire terminal so my a/c system will work......any help would be greatly appreciated...thanks in advance and may all have a good weekend.....also jeep is dead set on MOPAR parts due to Jeep and mopar agreements...personally I think mopar parts suck a%$ cause I have replaced nearly every mopar interior part on my jeep...are there any other quality manufacturers for the blower motor resister in case I have to buy a new one??????
  • Here is the update. I replaced the expansion valve and did a recharge myself. The air now blows cold air.... I can't believe it. Someone suggested to change that part and since it was only 26.99 i decided to give it a try. One thing, I can smell the outside air like its has an open vent. How do you know if you put too much 134a stuff? When I plugged in the gauge it was in the blue where it should be. I just want to make sure :)
  • eq9zeq9z Posts: 2
    My daughters 2002 Jeep Grand Cherokee has the usual problem with the actuator and blendor on the passenger side, no heat. The blower stopped working completely the other day and was diagnosed as the Resistor Harness, this was replaced. Now we can hear the blower going but the air seems trapped behind the dash. This was not the case before the Resistor went ou. Why would replacing this and getting the blower to work cause the air to be trapped? The air cond works at about 30% of the power it had just the day before...Did the mechanic block or move something?

  • barryzbarryz Posts: 43
    i have had a slow leak in r134, actually more than a slow leak, as i can top off and go through a 11oz can in 2-3 months, but thats much cheaper than repair, i have used leak detecter, could not find leak. Normal leak sealer was added, this product helps with leaks around rubber gaskets, it was no help. I found a product called super sealer which helps seal metal leaks as well. The first time i used it in summer 2009, it fixed the major leak and put it back to the old top off mode. This summer leak got bad again, i added super sealer again but it only held 3 months, so i decided to add 2 cans of super sealer this time, which my not have been smart. After adding, and then topping off r134 to bring to 45psi , it would not charge past 35psi, i kept adding, but gauge went no higher. I then drove in max mode for half hour, ac started blowing warm, compresser cycling. I figured it had leaked out and low pressure switch was doing its job. I put gauge back on, it was now 40 psi when compressor on, but when it cycled off and kicked back on as soon as it turned back on, gauge went north towards 100psi, where it would then kick compressor off again as if there is a high pressure switch also. Gauge would now head down again and kick compressor back on and it would stabilize for a while before going high and turning compressor off. I figured i had put to much super sealer gunk in. I let some r134 out through gauge, and it was more stable and cold except when first started and ac turns on, it now blows leak detecter and super sealer gunk out through a line on driver side of engine on initial turn on, then stops, same side as compressor but low and toward rear of engine. it blows this gunk out onto hot exhaust pipe causing lots of smoke. As soon as it burns off, all is well, as it stops blowing out in a few seconds. So now i know the area the leak is in, this must be a pipe returning hot r134 to compresor, as opposed to lines where r134 is added. I am hoping eventually i will seal this leak, once it blows enough of the sealer through the leak, each start up is less worse than one before it, and pressure on refill gauge is holding stable now. My question, what have i done to inner workings of system by over adding this super sealer, it says it does not harm,but 2 cans are not meant to be added at once. If i get the leaking line replaced, will this much super sealer in lines mess it up or will the process of evacuating lines clean it out? this sounds like i messed it up, but i did get 2 additional summers out of a high mileage 1999 JGC for minimal cost, wondering if now that leak has been spotted as a result, if simple repair will be good or has this sealer made a low cost repair impossible? Short term, i now have cold air and smoke at start up is getting less as excess sealer seems to blow out through leak at a slower amount on each start. Any advice?
  • bradyrbradyr Posts: 4
    I had my resistor motor and harness replaced the other day and the same thing was happening to me. It turns out that the mechanic had installed the harness incorrectly. The motor was actually turning backwards blowing air in instead of out. Have the mechanic check the wiring again or print an installation diagram then check the wiring.

    Hope this helps.
  • barryzbarryz Posts: 43
    reply to myself, went to my honest mechanic i trust, have appointment for him to survey my system, he says jeep is famous for the unit under dash leaking, i think he said its the evaporator, he also said all the gunk i put in clogged system, the stuff blowing out and smoking on my exhaust pipe is actually a high pressure relief valve trying to do its job. I probably caused this by putting in to much super sealer, but my previous r134 leak for which i could never find leak with leak detector, was probably that under dash unit, and since it is encased in plastic, i could not see all the pag oil dripping, its trapped in case. He says replacing this is extensive, requires dash coming out, he says if my compressor is still working, when he opens refrigerant lines to take evaporator out he will be able to de junk the lines and if the evap was the problem system will be ok if i did not burn compressor seals up, which i may have done. He says his survey will tell him if thats the problem or if its something minor, but in his experience evaporator is leaking. This is only $50 to find out, will probably do without ac till next spring and if my 99 jgc is still worth it, repair ac then. I'll post back with results of ac survey. I don't regret using super sealer as it got me through 2 summers, i could have spent big bucks last year to replace evap - labor is intensive, but now its a 12 year old vehicle with 165k miles, still runs ok, maybe next spring i will fix.
  • blendor,

    I am having the same problems as described above. Question is, how do you do the following: "You can lift the fallen recirculation door up off the blower and the air flow will be restored."

    Thank you for your time.
  • I see this is an old post, but I am hoping someone can help. The heat in my 99 Grand Cherokee Limited has completely gone out. I took it to a mechanic who told me the blend door motor needs to be replaced. He said the labor alone would be like $200 because he would have to take the dash out to fix it. I have read that to replace the blend door motor all that has to be done is take the glove box out and replace the motor. Will the entire dash have to be taken off or not? I have the fault codes, which are: 20, 54, 56. I just need to know if this is something I can fix myself and not have to spend hundreds of dollars to fix. It is getting cold and I have two small kids, and I need some heat !!! Help !!!
  • woowoowooty

    Check Message # 4674 it could solve your problem. How to go through the Glove Box.
    Was posted ... by folsomjeeper Jan 11, 2010 (8:50 pm)
    Hope it works for you.
    Best of luck to you.
  • First off, if you already haven't, review more threads in this forum regarding the loss of heat and get thoroughly educated on what's going on with the HVAC system. You sound like you have the same issue many have experienced. Your code 20 is the recirc door travel too large. The 54 and 56 are for the left and right blend door travel being too large. Your motors are probably still working! Your OEM blend doors are probably just laying inside due to them being a total POS and poorly designed and costructed by Chrysler. I just performed this yesterday and now have heat again. But my codes were 54 and 56 and my recirc door still works. There are several kits you can buy on the internet and ebay to fix this problem by going in through the glove box and replacing your blend doors. Not sure which to reccommend you choose as they both seem to do the job. Good luck and I hope you can do the fix and save yourself $1000. Don't go to Chrysler to buy the blend doors as I have heard they improved the doors but they are still POS compared to the guys' doors on ebay and the net.
  • Sorry woowoowooty .......
    I guess that message number no longer works ?
    Try this link for "Going through the Glove Box.

    Hope it works.
  • Good day all. I have a 01 GC Laredo. I am having an issue with low flow out of the Heater/AC vents. On Panel/Recirc, I get strong flow from the 2 center vents but only a trickle out of the side vents. On defrost or floor, I get very low flow from either. The fan works on all speed settings. Also, when going down the road, when transitioning to a passing situtaion or upshift, the flow cycles from whatever setting selected to defrost. Any ideas?
  • tuggajbtuggajb Posts: 646
    vacuum leak some where
    prob the storage tank behind front bumper most times leak is under battery where hose goes
  • My Cherokee has outside air (hot) coming in and raising the temp of the air. This is really noticeable when driving. There does not seem to be as much hot air being introduced when fan is on low. When fan is on low it is not possible to cool off the interior. Temps here now averaging 105 and it is quite humid also. My mechanic has checked out everything and says it appears to be under the dash but doesn't know of a "door" there. He is trying to avoid taking off the dash completely. Can anyone help?
  • nokluenoklue Posts: 1
    my a/c cruise control vacuum line broke off where it goes into the firwall in the engine compartment how do i fix it cant seem to find a diagram
  • dreinkedreinke Posts: 1
    I've been trying to determine what's wrong with the HVAC system in the GC. So far I've confirmed the recirculate door is broken and have permanently secured it in the recirculate position. I've cut the plastic behind the glovebox to determine if the blend doors work. They both move in the correct direction that's determined by the temp selection for each side of the system. The problem is there is no signficant volume coming out of the vents on either side of the car. No volume coming out of the defrost or the floor vents either. The fan is blowing hard which is felt when the plastic is open showing the blend doors. When the plastic is put back, there's still no air coming out of any of the vents. Any help is much appreciated.
  • jreadmondjreadmond Posts: 1
    ive been having a problem with my a/c working then not working. when the outside temperture is about 85 or lower the a/c works fine but when it goes higher then that it only blows warm air out. ive had it serviced and the freon level is good and so is all the pressures. please help with this. thanks.
  • rolo10rolo10 Posts: 1
    I have low/no airflow to just the passenger front vents, the center and driver's vent has good flow when panel selected. I have done the self test and no codes are thrown. I have looked at the recirc door thru the glove box and that is working. I see that at least the driver's side blend door actuator is turning and I don't have a problem with temp control. I have looked at the mode door actuator and everything seems to be moving in the correct direction and the airflow does change to defrost, floor and panel when selected. Any way to get eyes on the actual left/right mode door to verify motion other than pulling the panel? Any other ideas on what the cause might be on the dual zone system?
  • Hi jonnshell I just bought a G/C and having the same problem, have you found out what the fix is.
  • I have a 01 GC Laredo. I am having an issue with low flow out of the Heater/AC vents. On Panel/Recirc, I get some air flow from the 2 center vents but only a trickle out of the side vents. On defrost or floor, I get very low flow from either. The fan works on all speed settings.
  • How do you lift the fallen recirculation door up off the blower
  • on my way back home from a long trip my jeep over heated and i blew out the heater core ,i did a bypass and filled the cooling system but then it still over heated ,i left the radiator cap off an noticed it was back flowing so i changed out the thermostat but its still over heating and back flowing could this be the water pump failing to circulate or could it be some sensor that hasn't registered on my codes ?
  • jmarikjmarik Posts: 1
    Most of the air is coming out of the floor vents. This is ok unless it's really hot and you need the cold air conditioning blowing out the dash. Anyway, checked the vacuum hoses and found them to be ok, have plenty of vacuum. Had a mechanic look at it and he said that a part under the dash needs replaced. Means big bucks to remove dash. I am fairly mechanically inclined and would like to try to fix myself. Does anyone know where to find info. on how to remove the dash to access the air flow mechanism for the dash vents?
  • offroadpepoffroadpep Posts: 11
    edited August 2011
    jmarik ... Messages 407 & 408 may help you.

    Also check this page ...
  • sarnelsarnel Posts: 1
    Last night the air conditioner on our Cherokee just stopped working. The air conditioner light does not come on when you push the button; there is no air blowing out, no air coming out when the heat is turned on either. The light does come on when you push the defrost button. Please help.
  • rhickmanjrrhickmanjr Posts: 1
    edited August 2011
    I have a '96 JGC. When i'm traveling over 65 mph and it is hot outside there is a squealing noise that occurs. It appears to be coming from behind the radio cluster..more on the passenger side. It occurs if the A/C is running or not. If I slow to under 65 mph the squealing stops. It does not occur when the temp. is under 90 degrees outside so I never hear it in the winter or early morning summer hours. It does not occur if I travel over 65 mph and is cool outside. My conclusion is that a combination of temperature and speed is triggering this to happen. Anybody ever hear of this problem??
  • ok, I too am having the same crazy electrical troubles. I guess I still haven't seen what the cause is. My sunroof will come open on it's own, my a/c will now only blow on defrost only and will not change with the selector switch, my factory radio will not turn the volume up w/o spinning the knob several times, and my electric windows sometimes work and sometime dont, and my cruise now does not work. The light comes on but when I hit "set" I get nothing. Thanks for the help. Matt
  • 2005 Gr Cherokee heater ac blower operates in high position all the time. occationally operates in position 1,2, or 3. suggestions?
  • tuggajbtuggajb Posts: 646
    blower motor resister located in the heater box just to the left of motor held in with two 1/4 screws has 4 wires plugged into it
  • Thanks for the info. Found a vacuum leak right by the firewall in the engine compartment. A little electrical tape around the hose solved the problem. I save a bundle, I guess. :)
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