In cold weather, while using the windshield defroster, the hot air needed to keep frost off windshield suddenly changes to cold air on its own. This is very aggravating, and poses a great danger in not keeping the windshield clear. This happens very frequently. The dealership can make a repair, but the cost is prohibitive.

- Winston-Salem, NC, USA

HVAC auto temperature system fails to maintain/sustain heat/cold. Occurs constantly when driven. Fails to keep windshield free of fog/ice which impairs vision. Not safe to drive.

- Scott Afb, IL, USA

Several 1999-2004 Jeep Grand Cherokee that I have owned (I have had 4) had their blender doors malfunction. This results in a $1600 fee to have the heat/cooling vents repaired so you can get ac or heat. It is a chronic Jeep problem that deserves a recall as it happens to everyone's Jeep it seems. I have a current 2004 model where all three separate blender doors are broken resulting in no heat or cooling.

- Barrington, IL, USA

Heater sporadically works (blows cold air and defroster doesn't work) in my 2004 grand Jeep Cherokee overland. Problem usually self corrects after several hours of driving. Dealer states it is likely a blender door problem, but will not fix under my bumper to bumper extended Chrysler warranty until the problem presents itself in the dealers possession. So far, they claim it has not presented itself despite several trips to dealer.

- Portland, OR, USA

Failure of climate control "blend door mechanism. This has happened three times to this vehicle. When it fails, you cannot control the A/C or heat on each side of the vehicle. I repaired on both occasions at a cost of $900 and $700 respectively. The vehicle is now broken again, which will cost another $900-1200 to repair for the same issue. The dealership said this is very common in this model. Obviously a case of an inferior product or input for this component. I have contacted Jeep /Chrysler and they refuse to do anything.

- Greeley, CO, USA

Visibility: Defroster/defogger system:windshield:blower cold air blowing from defroster/heater system due to substandard components used by manufacturer resulting in defrost system failure that exists on these vehicles in year group 1999-2004. The manufacturer, daimler Chrysler has done nothing to resolve this issue with consumer/owners of their vehicles.

- Suffolk, VA, USA

The blend doors are breaking on my 2004 Grand Cherokee limited. They are known to fail after approx. 50K to 80K miles, causing the defroster to not work properly. This is a big safety issue, especially in the winter when the defroster is so essential.

- Fairfield, CT, USA

The blend door is broken and blows cold air. Window does not defrost and can't see well in winter.

- Des Moines, IA, USA

On are 2004 Jeep Grand Cherokee overland with automatic climate control the blend doors have failed and this causes the HVAC unit to either blow hot or cold when turned on but you have no control of it. We have had the A/C kick on when unit was set to heat/defrost in the middle of winter and this causes a safety issue as the windshield will start icing up or fogging up if it's not real cold out and as my wife drives this vehicle daily I want her in a safe vehicle. We have also had the heater kick on when using the A/C and all you can do is turn the HVAC unit off and roll down the windows. From what I have been told all Grand Cherokee's have this problem just at different intervals. I know some people who have had multiple failures of this part. To get the repairs done at a dealer we were quoted $950 to fix it but I believe Jeep should be looking into this as it is such a common problem and it causes a major safety issue during the winter months if and when the heater/defroster quits working. When the HVAC system gets stuck there is nothing you can do to fix it sometimes it will stick for a few hours other times it will not work for a day or two.

- Pleasant Hill, MO, USA

Research has shown all 1999-2004 Jeep Grand Cherokee with electronic dual climate controls will eventually require major repair in order to cure hot air/cold air blowing from vents when they're not set to do so. The cost to repair this issue, which has been known to pop up again after another 50K miles after repair, is generally $800-$1500 from a dealership.

- Tampa, FL, USA

The contact owns a 2004 Jeep Grand Cherokee. The contact stated that the heater blows cold air. The vehicle was taken to the dealer and they charged $97 for a diagnostic, but could not locate a failure code. She took the vehicle to aamco and they changed a hose and cleaned the vents; however, the failure persisted. She took the vehicle to a private mechanic, who replaced the thermostat and stated that the instrument panel main circuit board failed. A report was filed with the manufacturer and assigned reference number 18091070. The manufacturer stated that the mileage exceeded the warranty; therefore, they would not assist with the repair. The vehicle has not been repaired. The failure mileage was 82,000 and current mileage was 83,000. Updated 12/22/08. The consumer stated the heat didn't work, but the thermostat would get warm. The dealer informed the consumer that the blender and circulation board needed to be replaced. Updated 12/23/08.

- Wheaton, IL, USA

Dashboard has a loud creaking sound coming from its underside when turning on ventilation? there is creaking from the dash seconds after shutting the engine off. There are strange numbers popping-up on the climate control display. The cold ir blows from one side of the dash even when the heat is turned on. Research has shown all 1999-2004 Jeep Grand Cherokee with electronic dual climate controls will eventually require major repair in order to cure hot air/cold air blowing from vents when they're not set to do so.

- Bellevue, NE, USA

Had the defroster on. Tried to turn the blower to the vent position while fan was off and nothing came out. The defroster still works and the fan seems to be blowing, but for some reason, no air from front(outward facing) part of dash board. Had some knowledge of failure in the automatic climate control version, but specifically found Jeep with manual climate controls to avoid this problem.

- Amboy, MN, USA

Broken blend doors causing no heat for the winter on a Jeep Grand Cherokee.

- Mount Pleasant, SC, USA

The contact owns a 2004 Jeep Grand Cherokee. Immediately upon purchasing the vehicle, the sunroof would open, but failed to close. The contact never left the dealer and was informed that it was an electrical failure. The window regulator motor was replaced; however, the failure occurred on two more occasions. The contact returned the vehicle to the dealer both times and the motor was repaired. Shortly afterwards, the passenger side window fell inside the door. The contact returned to the dealer and was informed that the window cable failed. The mechanic repaired the window. Shortly after that, when the driver's side door was shut, the rear window fell down into the door. The mechanic stated again that the power window regulator was defective and repaired the failure. The manufacturer stated that the vehicle was not under warranty; therefore, she would not be reimbursed for the repair costs. The current mileage was 18,357 and failure mileage was 239.

- Edgewater, FL, USA

In April or may of this year, the driver-door window of our Jeep slid into the body of the door on it's own--this was while the car was parked on the street. We were lucky to catch it before someone stole all of our items in the car. A repairman told us that the cable/regulator is broken and that it is very common with Jeep. We couldn't afford the $250-300 part, so we simply screwed the window in place, temporarily. This past weekend while driving on the freeway at 65 mph our passenger window did the same thing. It was late Friday night so all we could do is duct-tape the window in place. We called Chrysler/Jeep to see if there is any recall, and they were completely unhelpful. They simply told us to get a $200 diagnosis from a Jeep dealership and then they would decide if Chrysler/Jeep would assist in the cost. We visited many consumer websites and found thousands (no exaggeration) of complaints of the very same problem. Those who ended up getting a diagnosis with a dealership never ended up being refunded by Chrysler/Jeep. In the end, they simply paid Chrysler/Jeep more money having gone through their suggested process. This is clearly and faulty part and Chrysler/Jeep's refusal to recall or reimburse its customers is alarming. The parts are very expensive and with so many complaints of the same nature we should not have to pay Chrysler/Jeep more money for something that is clearly their problem. Weather has nothing to do with the failure of the part(s)--they simply break without warning. Something must be done about this. Both of our windows are currently being held into place by screw or tape as we consider our options. We do not trust Chrysler/Jeep and believe that even if we go to a dealership we will end up paying for the repair all on our own. It is a considerable expense for a common default and has given us a great deal of stress. Chrysler/Jeep representatives have been unsympathetic, ambiguous, and untrustworthy. Please help!

- Alameda, CA, USA

My 2004 Jeep Grand Cherokee limited with the automatic climate control system, blows cold air out of the passenger side floor vents even when set to heat. This is a current and ongoing problem, it occurs whenever the heat is needed. Nothing has been done to remedy the problem, waiting for a recall.

- Fargo, ND, USA

Defroster on my 2004 Jeep Grand Cherokee only blows cold air.

- Sparks, NV, USA

Normal operation of heating/cooling system. Now, after 28,000 miles, temperature will suddenly change in the cabin of the vehicle. The heat will suddenly cease and the visibility will be lost out the windshield. I believe it may have something to do with "blend door". when the windshield frosts up, we have to pull over and turn car off and wait for system to reset. Very dangerous, not safe, dealership estimates $1,500 to $2,000 to repair.

- Scott Afb, IL, USA

I was just riding down the road one day and my air conditioner quit working. I ran the test on the Jeep and it gave me codes dealing with the blend doors staying open.

- Shelbyville, KY, USA