Why does my Jeep heater only blow cold? Why is there heat on only one side in my Grand Cherokee ? How do
I fix my heater? If your Jeep Grand Cherokee heater only blows cold on one side all of a sudden, or seemed to
just quit producing heat one day – you most likely suffer from blend door failure.
Blend doors are small airway control doors that move into positions to blend hot and cold air to your liking based
on where you have the temperature setting knobs positioned. These little plastic flap doors hide behind your glove
box in your A/C system’s housing, and move up and down to pass heat or cold air as you command.
The material has caused them to be weak and brittle allowing them to fall apart leaving you with icy cold air as the
only option. That’s fantastic if you live in Florida or Arizona in the summertime but for the rest of us we are going to
need our heater.
Take a few moments to watch the videos and dig through the photos to make sure you fully understand why your
Jeep has no heat, and how to fix this common problem all by yourself, right in your own driveway using only a few
simple tools. Complete the final Check List here.
If you are still not sure the Jeep Heater blend doors will solve your problem – Read on. We have outlined a way
to see if your heater blend doors have failed.
If you have no heat on the drivers side – this test will work for you.
If you only have no heat on the passenger side only, please use the electronic method outlined above.
Please follow the steps below. This method involves a little disassembly but is a great way to ensure our Jeep
Heater aluminum blend doors are the right solution for you.
Easy and FREE Self diagnosis for you Jeep Heater
The code numbers will be displayed on the screen one at a time.
22 or 54 Left temperature door is broken or 47 – motor not responding.
24 or 56 Right temperature door is broken or 48 – motor not responding.
54-56 are the most common and our Blend Door replacements are exactly what you need to get your Jeep
toasty warm again.
For more failure codesclick here
Try this free vehicle diagnosis on you
Jeep Grand Cherokee and see if we
can help. If you see the codes 54 and
56, you are in the right place! Our
JGCParts Heater aluminum door
solution will restore your Jeeps heat
Once all codes have been displayed,
the system will repeat the fault code
numbers. This will continue until the
ignition is turned off. Record all of the
Our JGCParts Heater blend door kits will fix your heater or we’ll buy it back.
This is primarily an issue with all Dual Zone climate control systems in the 1999 –
2004 Jeep Grand Cherokee .
These plastic doors (blend doors) are what determines how much heat and cool air
you receive when you turn the temperature knob on the dash. If you turn the knob
for hot air, they move up. If you turn the knob for cool air, they move down.
These little doors are made of a cheap plastic that falls apart after a while allowing
them to fall down in the cold air position. This causes the loss of temperature control
– mainly the loss of heat.
The OEM factory made blend doors are cheap and prone to cracking. The little drive motors used to move them up and
down are very strong and can put too much pressure on them causing them to crack, break and eventually fail. Once
broken – your heater stops working.
Unfortunately it will cost up to $1500.00 and 3 days of no Jeep .
So why does it take so long, and more importantly – wheres that $1500.00 of your money going?
Labor Charges! The dealerships and auto repair centers do things by the books and they have plenty of reason to.
Lots and lots of labor when done their way.
The dealerships rules require them to drop the steering column, remove the center console, evacuate the AC system,
pull off the entire dash, drain out the vehicles coolant, disconnect the heater core and disassemble all of the heater box.
That’s a ton of work and flag hours. That adds up to big bucks for them. That’s good for the ASE certified mechanics
who are getting paid for all that work, but a huge pocket drain for the Jeep owner who has to dish out all that cash.
Do you have the problem?
The usual symptoms are that one side of the cabin will loose heat, followed by the other side at some point.
Air Conditioning is working on cold but not hot no matter the control knobs setting.
Limited / Overland :Grand Cherokee Dual Zone Control
These have automatic zone control and the driver and passenger sides have individual controls.
You can electronically read the fail codes on the system by following this procedure:
Lower the glove box
Remove the drive motor
Cut a small hole in the plastic HVAC box
Remove the broken blend doors
Install the new JGCPartsHeater blend door kit they just slide in
Replace the piece of plastic you cutout
Replace the drive motor
Close the glove box Your Done!
It’s really that easy! The hardest thing to do is make the first cut.
This job will take between 30 – 45 minutes for most people.
Click here for complete online detailed instructions with photos
Click here for printer friendly instructions
Choose an option below for more detailed instructions with photos
Click here for printer friendly instructions
JGCParts Heater Dual Zone blend doors for all 1999 – 2004 Jeep Grand Cherokee .
The easiest, cheapest way to fix and restore heat to your Jeep.
Jeep Heater Dual Zone blend doors for all
1999 – 2004 Grand Cherokee . The sure way to
fix and restore heat to your Jeep .
Make the smart choice.
Do you have the problem?
The usual symptoms are that one side of the cabin will loose heat, followed by the other side at some point. Air
Conditioning is working on cold but not hot no matter the control knobs setting.
Laredo :Grand Cherokee Single Zone control MTC
Our single zone control can be used on ALL 1999 – 2004 Grand Cherokee vehicles! On models with dual zone
control, the dual control feature will be lost.
To diagnose your Laredo MTC A/C System:
There is no electronic diagnosis available for your Jeep .
Physically check the operation of the blend doors by removing the glove box.
Remove the blend door motor which is located to the side of the opening.
The motor is held in place with two Phillips screws.
Disconnect the wire harness and remove the motor.
You will see the plastic axle that is connected to the
blend door. There should be a limit pin on the white
The failure occurs because this pin breaks, putting the
force of the motor directly to the shaft of the blend
doors. The cheap plastic shafts can not stand the force
of the strong drive motor and eventually crack resulting
in blend door failure. That equals a blocked heater
core and loss of heat.
Start the Jeep and turn on the AC.
Manually switch between heat and AC by turning the axle left and right with your fingers. If there is no change
between cold and hot while turning the white connector, your blend doors are broken and the JGCParts Heater
repair kit is your solution.
Option A:$1500.00 and 3 days later, with factory
made to fail parts, and that creepy mechanic guy over
there will have it ready for you.
Option B:$150 and about 45 minutes of your time,
using solid aluminum JGCPartsHeater blend doors
and you’re good to go.
I’m on a budget and I’m freezing. How easy is it to install?