Jeep Grand Cherokee HeaterTreater blend door heater fix

HeaterTreater has been in business for over 10yrs and we have thousands of installations in GC's around the world(including RHD's). We have developed a complete line of products for Chrysler/GC/Ford and have universal solutions that will work in any automobile. WE ARE THE EXPERTS and guarantee successful installations and will provide any help required to get it right(English orish). Our products are made-in-USA steel, not cheap Chinese plastic copies. We have hundreds of authorized garages across the US that can do the installation if you prefer not to do it yourself.

USE WHAT THE PRO'S USE. Our steel doors will outlive the GC and provide superior performance.

The plastic (copies) are knock-offs our our original invention and are a poor solution for long term reliability. We can't match the price on the cheaper Chinese plastic parts, but if you want better American made parts with a 10yr successful installation record on the GC, HeaterTreater is the answer.

You won't ever have to worry about failure at an inopportune time. Kindergarten Physics: You may hear comments that the steel doors are too heavy and stress the actuator motor. Two things to consider: 1. The doors are heavier, but the bulk of the weight is in the axle.

Like a fat guy sitting in the center of a see-saw, the weight doesn't make a difference, just the ends of the see-saw. The weight of the metal door provides strength and stability beyond what can be achieved with plastic and won't ever break.

The actuator motors have waaaay more torque than required for moving the blend doors. ACTUATOR MOTORS There are now a lot of GC actuator motors showing up in all the listings.

We've replaced thousands of doors and have NEVER seen a bad motor. It's a simple two wire DC geared motor. We do see failures on Ford and Chevy and later model GC motors that have internal electronics, but not this model GC. A lot of technicians make the mistake of turning the temperature knob and observing that the motor doesn't turn and assume that it is bad. Actually the HVAC computer controls the motor and shuts it down when it senses fail codes. The motor isn't bad, just suspended operation from the computer control. The video is a little long and wordy, but it will give you a good overview of the repair process and the skills needed to complete the repair.

You will find that the repair is actually very simple and you can have full confidence that the HeaterTreater team will provide any support that you might need to complete the repair. Our team members are the experts in the field of aftermarket blend door repairs on multiple automobiles and have a record of 100% successful installations and are committed to maintaining that record.

We take pride in our excellent customer feedback and 100% record of successful fixes on Grand Cherokees. Our products are over-engineered to insure long term reliability and flawless operation. The HeaterTreater will outlast the GC and we guarantee support and any replacement HeaterTreater hardware for as long as you own the automobile. Check our other listing for the re-circ door fix also.

Both fail modes are common on the GC, and you need to check the operation of both systems to fully understand problems. We have three different repairs for the GC blend door: 1. Standard HeaterTreater- converts dual control to single control from the driver's side. Dual Control HeaterTreater - Retains dual control by adding a second motor "Piggyback" onto the existing from motor.

Requires more work, but if dual control is critical, this is the easiest way to repair the system and keep that function. HeaterTreater PRO - Basically replaces the OEM plastic with metal. Requires complete disassemly of the dash and removal of the heater box. Most customers choose this only if they have to remove the box anyway to replace the heater core or AC evaporator core. We also have a repair for the re-circ door, but this failure takes longer to occur and can usually be put off.

Check FAQ #2 for some simple diagnostics. Video's of both repair procedures are available in our online tech section. This is a kit to do a complete repair on the blend door malfunction that is common to 98-2004 Jeep Grand Cherokees. It will work equally well on a RHD or LHD GC.

The most common symptom is a failure of the passenger compartment heating system, however about 10% of the time the driver's side fails first. This occurs because the broken blend door falls to the bottom of the box and blocks the heater core.

While loss of heat is the most common symptom, the door can fall into different positions and even shift or rattle around. AC can also be severely impacted and at least compromised with a "gravity" seal against the heater core in place of a blend door held in correct position by the actuator motor. Every Grand Cherokee in this range either has, or will have, this common failure. The pictures show a before and after shot of the blend doors. Once completed, the alterations are behind the glove box and are not visible.

The work to install the fix is very simple. Check the video on our web site to get a good overview of the process. The product changes the dual control Limited GC to a single control from the driver's side temp control knob. We do have products to maintain dual control, but most choose to lose dual control in favor of a cheap and easy repair...... Single control vs dual control. The Cherokee is built with Blend Doors to control the heater and AC function. The controls are either dual control (Limited version) for separate passenger/driver control or a single control system(Laredo version).

The doors are controlled by a DC motor that seeks an open and close setting every 20 times the Jeep is started. During this calibration routine the motor is overdriven creating excessive force on the components. The end points for open or closed are set by a plastic pin that is part of the plastic door assembly.

When this pin breaks, the stop points become the open and closed position of the door. Eventually, the doors will break(see picture). The most common fail mode is for the broken door to fall to the bottom of the box, blocking the heater core. Also, in this position, the door does not do an efficient job of blocking the heat input, and the AC efficiency suffers. The door can also hang in a position where it closes neither the heater core nor allows full flow through AC evaporator. When this happens, you have a constant mixture of heat and ACtoo cold in the winter and too hot in the summer. The Factory solution is to replace the doors and housing with an upgraded part that has a wider plastic limit pin to withstand the constant opening and closing when the stepper seeks its beginning position.

The repair entails removing the dash panel, steering wheel, all vacuum and wiring harnesses, draining the coolant, evacuating the AC system, and finally removing and repairing the heater box. If you can find someone willing to spend two days disassembling the car. It's not difficult, just detailed, and evacuating and refilling the AC refrigerant requires EPA certification.

Dealers don't like to do this because it ties up a technician for an extended period of time and the chances of missing a wire or causing additional problems during re-assembly is high. Do you have the problem?

The usual symptoms are that the passenger side will loose heat, followed by the drivers side(although driver's side first is possible). AC is marginally acceptable, but eventually there will be no heat on either side, and poor AC performance since the broken door is not fully sealing the heater core.

Grand Cherokee Single Zone control(usually Laredo). The blend door failure is not as common on the Laredo as the Limited, although it will happen, it just takes longer. Since the blend doors are connected together and operate from the same motor, they offer more resistance and take longer to break. You can physically check the operation of the blend doors by fully swinging out the glove box. There are two removable rubber stops at the top of the box opening and in early models, a dampener arm on the right side of the box(took them out in later models, and I'd suggest that you do the same).

Check the web site video to see how to open the box. With the glove box open, you can see the blend motor to the left of the opening. The motor should move when you change the temperature setting. However, failure to move does not indicate a bad motor. The computer will shut the motor down if it detects a system fault.

Either way, you need to remove the motor and check the axle before any diagnosis is possible. The motor is held in place with two Phillips screws. Disconnect the wire, remove the motor and you will see a plastic axle that is connected to the blend doors. The axle should have a limit pin on the white plastic axle(like the comma on a "Q") The GC failure occurs because this pin breaks, transferring the force of the motor directly to the blend doors.

When this happens, it's just a matter of time before the doors break. Check for a broken limit pin on the axle and check that you can turn it 80 degrees of movement between the two stop points. Start the GC and turn on the AC. You should be able to manually switch between heat and AC by turning the axle with your fingers.

If the motor is spinning and not stopping, or the blend doors are not switching between AC and heat, your blend doors are broken and the HeaterTreater. If everything is working properly, the blend doors are not the problem. You might want to check our other listing on the re-circ door. Grand Cherokee Dual Zone Control(usually Limited).

The limited has automatic zone control and the driver and passenger sides have individual controls. You can read the fail codes on the system by following this procedure. Turn the ignition switch on and turn on the AC system.

You should see a temp display for the two sides. The codes will now flash on the temperature LCD display.

The most common codes are 52,54,56. 54 and/or 56 are a definitive diagnosis of blend door failure and the HeaterTreater is your best option for a repair. 52 indicates a problem with the re-circ door. Check our re-circ door product listing or FAQ #3 on the web site(heatertreater. Below is a listing of all the HVAC codes. The lower number is a transient real time code and the larger number is an historic code. You can clear all codes by holding down the AC button for 20sec while in diagnostic mode. The codes will be re-generated the next time the system goes through a calibration(every twenty times the GC is started). Left temperature door not responding.

Right temperature door not responding. Left temperature door travel too small. Left temperature door travel too large.

Right temperature door travel too small. Right temperature door travel too large. Re-circ door travel too large (check our re-circ door listing). You can also follow the diagnostic procedure listed above for the Laredo to physically check the operation of the driver's side blend door.

However, the blend door axle that you access is for the drivers side only. The passenger side motor is buried behind the heater box. This kit replaces the plastic doors and axle with steel components. All work is done through the glove box opening and no disassembly of the dash or evacuation of the AC system is required. Tools required are a phillips screw driver, pair of pliers, and a Dremel tool.

If you don't already have one, this is a good excuse and the tool has many uses. Dremel bit, sealing HVAC tape, and all hardware is provided. The repair will take about an hour, and once you have experience, you can do a second GC in about half an hour. No extensive mechanical skills are required. The kit is configured to change the dual control to a single control from the driver's control panel.

This is a necessary compromise to insure the long term life of the fix. Both sides will have the same temp setting with a single control.

The passenger side knob still looks like it works and you can adjust the temp display, it just doesn't do anything. In the picture, you can see what your blend doors probably look like. The pictures are taken on an assembly that was removed from a Grand Cherokee. The second picture shows the metal replacement kit. The third picture shows the axle that is used to control the doors. It is ground to fit the motor fitting. Note the steel roll pin going through the axle. This is the new motion control stop, replacing the plastic stock solution. The next picture is of the doors installed in the system and a picture of what the fix will look like when finished.

All this is behind the glove box, so it is not visible when the glove box is back in place. The plastic doors are accessed by using the Dremel tool and bit to cut into the plastic heater housing.

Complete diagrams for the cutting pattern are provided. It's a very simple process. The broken plastic doors are removed and replaced with the. The instructions are written with multiple pictures and dual level instructions.

You can read the bold print only for experienced mechanics or read the bold and standard for full "instructions for Dummies". The instructions are almost insultingly simplistic for those who care to read the entire document without admitting that they did it. The fix is really easy and MUCH preferable to dis-assembly the entire dash and engine cooling systems. We are the inventors and originators of this repair methodology for the Jeep and other vehicles, including Fords, Chevrolet's, Chrysler and as universal kit that will regain control over any modern vehicle.

We are a team of degreed engineers and are the experts in automotive HVAC systems and have many after-market kits for different vehicles. The other products listed for the GC are copies and/or direct theft of the technology that we developed. We have a 10yr record of excellence and will provide any expert advice required for the installation of our products.

With any of the other guys, you're on your own. In a way we are flattered that copy-cats consider our engineering to be so good that they can copy and sell product with no concern for support. We maintain a full staff of support personnel and can guarantee satisfaction. Beware of dual control solutions that just plug a door onto the back motor axle. They don't understand the physics and failure of the system and are providing a solution that WILL fail again and cause more problems than the original problem.

We deal with scammed users constantly and even developed a solution kit... Here is the problem with that approach. The original failure occurs when the plastic limit pin on the drive axle breaks and force is transferred from the limit function to the actual door. The plastic door can't withstand the force and the motor connection breaks, causing the door to fall to the bottom of the box and block heat.

When you just plug another door on the axle, the force of calibration is absorbed by the nylon motor axle. The new door is strong enough to withstand force, but the little plastic motor insert is not. It will bend and cause calibration problems and eventually break off. It's easy to remove the front motor and examine the nylon axle insert. Note that it is hollow and not built for excessive force. When it breaks, it's easy to replace the front motor, but the back motor requires complete dis-assembly of the dash and plenum box. The plug in dual control "repair" will work for a while, but it will just break again. The good news is that we can tell you how to fix it correctly after it fails. The Chinese plastic replacement doors are a temporary fix for the problem. They will break again and usually at the most inopportune time...

We can't compete on price with Chinese plastic or rip-off artists that have no development or support overhead. You get what you pay for and we feel that American made components from the leading experts on HVAC to be a good investment in your vehicle.

Of course, we are a little biased with this opinion, but you get what you pay for. Customer Feedback You can also check my feedback listings for additional customer comments. Just want to say thanks for such a great invention!

Installed it last nite and by dang it actually works!!!! You got something there i tell you! Good luck on more sales, you saved ME a fortune. I finally got a chance to install the heater treater and it fixed the heat on the passenger side just as advertised.

The heater box on my 2002 Jeep Grand Cherokee Limited was slightly different from the diagrams but was fixed easily. Easily installed and HIGHLY recommended. Still sucks that everyone has this problem, but mine is NO MORE! I just got my HeaterTreater and went to town with it!!

I read the directions for longer than it took to put in!! The worst part is simply the scare factor of cutting into the plastic housings!! It went very, very smooth - and my Heat and Air work again!

As described, the dual climate control no longer works, but the drivers control operates both sides. Not a problem for me, since I usually turn both to the same setting anyway!! HeaterTreater is a reliable product designed by degreed professional engineers with significant experience in control theory and materials science. We dont claim perfection, but have over-engineered this and multiple other solutions to exceed functional requirements.

The HeaterTreater is the original and best product and we will bend over backwards to make sure that the system works in your GC, and fully stand behind our products. The item "Jeep Grand Cherokee HeaterTreater blend door heater fix" is in sale since Tuesday, February 10, 2009.

This item is in the category "eBay Motors\Parts & Accessories\Car & Truck Parts\Air Conditioning & Heat\A/C & Heater Controls". The seller is "texster68" and is located in Austin, Texas. This item can be shipped worldwide.

Other Part Number: 902-320
Warranty: Yes
Brand: HeaterTreater
Country of Manufacture: United States