What would you like to do?
How do you fixs blend door?
For the 99/04 WJ Jeep Grand Cherokee there are two ways.
One is to remove the dashboard and HVAC box from the vehicle.
The other way to replace the blend doors is by cutting an access hole.
A short version of how the access hole repair is done.
Disconnect the Negative battery cable.
Lower the glove box - by hand
Remove the actuator motor - You will need a Phillips screw driver
Cut an access hole in the plastic HVAC box - I supply a multi-purpose cutting bit, you will need a rotary type of cutting tool, like a Dremel, RotoZip, etc. Or you could do the cutting by hand with any type of small cutting tool, it will just take longer doing it by hand. Or some customers used a narrow pointed soldering iron!
Remove the broken blend doors - by hand
Install the new aftermarket access hole blend door kit - easy, just slide the new doors in place - NO screws or other fasteners needed.
Close the access hole - Replace the wall piece of plastic you cutout - Apply an aluminum tape to cover the groove made by cutting the wall.
Replace the actuator motor.
Close the glove box - Your Done!
It is almost as easy as what you just read, the hardest and the most time consuming thing to do is cut the access hole.
The job should take between 30 minutes to 1 ½ hours. Depending on how long it takes you to gather your tools, etc.
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The blend door regulates heat and AC in today's automobiles. Generally the system is set up with air always flowing through the AC evaporator coils, and the compressor is eith…er on or off, cooling or neutral under system control. Now the air flowing through the evaporator is either directed into the vent system, or directed through the heater core and into the vent system. The blend door regulates the amount of air that is allowed to go through the heater core. For AC, the compressor is on and the blend door blocks air flow through the heater core. For heat, the compressor is off and the blend door diverts air through the heater core. Those are the two extremes, and exacting temperature control is achieved by having the blend door in intermediate positions between the two extremes. Remember the slide bar on the AC control panel on older cars? That slide lever was connected by cable to the blend door and temperature control was achieved by sliding the lever. On modern automobiles, that function has been transferred to computer control, using a pseudo stepper motor to control the blend door. On late 90 and early 00 cars, the motor was connected to the same plastic blend doors that were used with the slide scenario and there is a recurring problem over time with the motor being too strong and breaking the plastic blend door, leaving no control over temperature. The fix is to remove the heater box, which is a very involved operation, and replace the plastic door(which WILL break again over time). Additional information on the cause and a cheap easy solution is available at HeaterTreater at www.heatertreater.net, or follow the Google ads on this forum. cgallen
A blend door is short for Blend Air Door. There are other names such as temperature door, etc.. The blend door, blends or mixes the hot air with the cold air. There usually is… an actuator motor that opens and closes the blend door a little at a time to adjust how much hot air and cold air to mix for the temperature setting you have chosen. If your blend door or doors are broken sometimes you will only get cold air coming thru the vents or maybe just hot air with no air conditioning. For more information on the fault codes, etc for the Jeep Grand Cherokee blend door problems, checkout the Blen Dor Store on Ebay. There is an easy blend door replacement kit with only two parts to install. No Dashboard Removal. The Blen Dor kit is guaranteed for as long as you own the vehicle. For more information try a search for Blen Dor . Close, but not exactly. On most modern vehicles, air is constantly blown through the AC evaporator core and then the blend door can divert some or all of the air through the heater core. In full AC mode, the blend door is closed against the heater core inlet and all air flows around the heater core and directly into the vent system. In heater mode, the compressor is deactivated and the air flowing through the evaporator core has no temperature change. As before, the blend door will now direct some or all of the air flow through the heater core and into the vent system. In the old days, the blend door was controlled by a slide lever on the AC panel which was connected to a cable that ran to the blend door. In the mid 90's most automotive companies went to computer control over the blend door, using a pseudo stepper motor to control the door. A common design flaw in these systems is the end point detection for door movement. For a computer algorithm to control the door, it has to "know" when the door is closed against the heater core or blocking the free flow of air through the vent system. This is done by driving the motor and door to a stall point and detecting a voltage surge from the motor as a digital signal indicating the end extent of movement. The catch is that over time the plastic doors cannot withstand the over-stress of the calibration routine and will break. When this happens, all control over heat and AC is lost. The problem is common on multiple vehicles and HeaterTreater has built a line of products for the most severe cases. We are always looking for additional applications for our repair technology and would be happy to discuss how we can provide a solution for your particular issue.
The blend door sits vertically in the heater box behind the glove box. If you fully open the glove box, you can see the actuator motor on top of the heater box in the upper …left hand corner. On the bottom of the box is a "pedestal" that is the bottom axle point for the blend door. The door axis is between the motor axle and the pedestal. If you are having issues with a Ford Ranger blend door, you can find diagnostic procedures with pictures and a cheap easy solution to the problem at HeaterTreater www.heatertreater.net, or follow the Google ads on this site. cgallen
Ford changed the plenum box in the Explorer in 2003 and the system is completely different from the previous models. However, the 03+ model years suffer from a similar b…lend door problem as the earlier models. The early models have a wear-out problem with the door breaking from constant stress of calibration. The newer model has a problem with the design of the system forcing the door out of alignment when it is moving. The stress is constant and results in a broken door sooner than the typical wear-out mechanism on the earlier models. The technical explanation is a little involved without pictures and arrows. Check the Tech section on heatertreater.net for pictures and a full engineering evaluation of the system.
Very difficult, as it is underneath the dash, which is hard to remove.
On a 1996 Ford Explorer : The blend door would be INSIDE the plastic case that has the heater core ( and air conditioning evaporator if equipped with A/C ) located below the g…love compartment
Directly on the Back left side of your blower motor, two Gold screws hold it in place. One easily visible, the other is hard to reach.
I'm not sure if Mercury followed Ford with the introduction of the new HVAC system in 2003. That is probably the case and the system and problems will be the same as t…he Ford Explorer. Pictures to identify which system you have and diagnostic processes are available on heatertreater.net.
The Grand Marquis uses the same HVAC system as the Ford Taurus and Mercury Sable and all three automobiles suffer from the same blend door failures. The actuator is lo…cated on the front side of the plenum box and you can see it if you fully open the glove box and look to the left over the transmission tunnel. The recommended dealer fix is to remove the dash and plenum box and replace the plastic door. There is a kit on Ebay from HeaterTreater that offers a cheap easier fix for this problem.
Assuming you are going to replace the 99/04 Jeep Grand Cherokee blend doors yourself. You would start by disconnecting the negative battery cable. If you are going to remo…ve the dashboard, etc to replace the blend doors. some websites give you complete instructions with plenty of pictures. It will take the average person with little or no auto repair skills approximately 12 to 16 hrs. The vehicle will have to be taken to a shop that can recover the refrigerant before you start removing the dashboard and HVAC box.. If you are going to do the type of repair where you cut an access hole in the side of the HVAC box. A short version of how the access hole repair is done. Disconnect the Negative battery cable. Lower the glove box - by hand Remove the actuator motor - You will need a Phillips screw driver Cut an access hole in the plastic HVAC box - I supply a multi-purpose cutting bit, you will need a rotary type of cutting tool, like a Dremel, RotoZip, etc. Or you could do the cutting by hand with any type of small cutting tool, it will just take longer doing it by hand. Or some customers used a narrow pointed soldering iron! Remove the broken blend doors - by hand Install the new Blen Dor Store dual control kit Replace the actuator motor. Close the access hole - Replace the wall piece of plastic you cutout - I supply an aluminum tape to cover the groove made by cutting the wall. Close the glove box - Your Done! It is almost as easy as what you just read, the hardest and the most time consuming thing to do is cut the access hole. The job should take between 30 minutes to 1 ½ hours. Depending on how long it takes you to gather your tools, etc. --------------------------------------------------------------------------------------------------------- Video's of the repair and expert support are available online. Check for a full explanation of the problem and repair process. Again disconnect the negative battery cable first. This type of repair takes an average of one hour to complete. The work is done behind the glove box. You would cut a 5" x 3" access hole. Remove the broken plastic blend doors, etc Install the new aluminum blend doors, drive connector with stop limited pin. Replace the cutout section and apply an aluminum foil tape on the cut line.
The blend door actuator on the late model Chevy Tahoe is located behind the dash in the glove box area. Broken blend doors and broken blend door actuators are a very common pr…oblem among Chevy Tahoe, Suburban, and Silverado models. Typically, to repair a broken blend door, a mechanic will disassemble the dash and replace the plenum box. It is an expensive and labor intensive repair. There are also some DIY solutions such as the heatertreater that provide hardware and instructions for performing the repair by removing the glove box rather than the entire dash. It is worth looking into if you think you have a broken blend door.
There is no significant power at the three wire plug at the control knob, the three wires are directly wired to a potentiometer. In the five wire plug on the actuator there is… a ground and twelve volts. To test knob, use a multimeter to check for changes in resistance from the middle to the outsides, and for a constant resistance on the outsides. Use a voltmeter to check for 12 volts at the actuator plug, hooking to the two wires that are diff colors than the three that go to the control knob. If you have 0 volts with key in run position, you prolly have blown fuse. The knob resistance can be checked regardless of key position. If turning the knob varies the resistance, and you have twelve volts in run, then your actuator is probably bad. iF turning the knob yields no change in resistance, than the knob is slipping and not turning the shaft it sits on.
the blend door actuator is located under the sound insulator panel. Remove the sound insulator panel by removing for 7mm screws. Move the sound insulator panel out of the way.… Now look at the bottom of the heating/air conditioning unit at the bottom near the carpet where the transmission hump is in the floor board. You will see a little 3 inch by 3 inch black box with a 6 wire plug going to front of the box. Unplug the actuator and remove the 3 (7/32) screws. When putting in a new actuator DO NOT PLUG IT UP TO TEST IT. IT WILL THROW IT OF TIME. The only thing you need to test is the blend door. Turn the bottom of the door where the actuator connects to door and check for movement. put on new actuator and start fixing your next problem
In Ford Ranger
The blend door on my 1988 ford ranger is stuck in the cold position. any quick fixes or do i have to have it professionally fixed?
Answer . There is a mechanical lever on top of the heater that you can reach if you remove the plastic covers under the dash, just flip it to the other side.
IF the system is the same as the Mazda pickups and Mazda Navajo, HeaterTreater has a product that will fix the problem. Mazda diagrams are hard to come by. If you check …the pictures on the Ebay listing, you should be able to determine if the fix will work.
First, determine whether or not the door needs to be replaced. If it does not, then assess the amount of damage done to the door. If it only needs new hinges, screws, or handl…es, then these items can be purchased at your local home improvement store. Most doors can be fixed inexpensively, eliminating the need to replace the door altogether.
Its behind the radio/CD player. To service it, you must spend 3 hours taking everything apart to get to it.