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Ford Explorer Air Conditioner and Heater Problems



  • no i havent been able to get it fixed as of yet, and its still freezing cold, i tried the fix heater treater suggested but that wasnt it so i go to the next step tonight if i have anyluck i will advise asap
  • I think the broken lever is a symptom of, not the cause, of loss of heat. The lever is connected to the blend door axle and it's position is set relative to the blend door. The lever actuates a vacuum switch when the door is rotated to the full max AC position. The switch applies vacuum to a heater hose valve that is activated to shut off coolant flow when the button is pushed by the lever. The idea is to increase AC efficiency by shutting off hot water flowing through the heater core and remove any radiant heat from the plenum box.

    The lever that pushes the button is on the passenger side buried deep under the dash panel. Even my wild-child youngest son couldn't kick it and break the lever. The question is why the lever broke in the first place. It would be possible if you really tried to physically break it, but it would take a contortionist in a frenzy.

    Two things to check:

    1. The lever itself has no effect on the heater, only the opposite concern of making the AC more efficient. If the problem is related somehow to the lever, it would have to be that the switch is also damaged and stuck open and shutting down coolant flow. You can locate the vacuum actuated valve under the hood and see if the heater hoses are hot on both sides of the valve. This would indicate that the valve is open(fail safe mode) and heat is reaching the heater core. This doesn't explain how the lever broke, only tracing symptoms that could be related to the lever.

    2. The blend door can break off from the axle, allowing the axle to spin past the point that it would normally stop at. If the axle is turning past the normal stop point for max AC, it would also torque the lever harder against the vacuum switch and has enough force to break the lever. If this is the case, the door could be broken off an lying dormant in the bottom of the box, blocking any air flow through the heater core. This would explain the broken lever and lack of heat. If the heater hoses are delivering hot water through the firewall into the heater core, this would be a likely explanation.

    What we need to know is whether heat is getting to the core and if it is hot, why the blend door is not allowing air flow through the core. The actuator motor is located under the driver's side dash and is tricky, but possible to get to. You need to locate the motor, remove it and examine the motor side of the blend door axle. You should be able to turn the door with a flat angle bracket piece of metal and manually switch between AC and Heat by positioning the blend door differently. If the door is OK, the motor has to be suspected. Check the HeaterTreater web site for information on how to check the motor with a 9V snap battery. If the door is broken, you have a choice of paying the dealer an arm and a leg to repair it, or do it yourself with the HeaterTreater fix. It's not easy since Ford did not anticipate HVAC failures and access to the components was not planned as a standard repair operation. That's why the whole dash has to be removed for the dealer approved repair. The HeaterTreater takes a little "creative persuasion" and a couple of bandaids, but it can be done, and once done you have metal components that will never break again.
  • Update to message #78:

    My fix is not working any longer, so it lasted less than one year. I'm going to try and see if I can get it to work again. I put a lot of money into my Explorer this fall (what was I thinking?!?), so I don't want to invest a lot more, but I (or more specifically, my wife) needs heat!
  • Update to message #162:

    I posted too soon again. The blend door fix is still in tact. It looks like my heater core is plugged. The hoses through the firewall are not very hot. How hard is it to replace the heater core on a '97 Explorer? Or can I blow or flush it out?

  • I'd take a shot at flushing it first. Prestone makes a good kit for flushing the coolant system and I've seen it at WallyWorld fairly cheap. You can always just use a garden hose splice connector from Home Depot to connect the heater hose to the water hose and flush the core by itself. The Prestone kit has some fancy super secret chemicals that are supposed to be better than just flushing with water.

    The Explorer also has a vacuum actuated valve on the heater hoses to turn off flow of coolant through the heater core when running Max AC. The problem could just be a malfunctioning valve that is easy and cheap to replace. You can always just take the valve out of the loop and connect the two connections to the valve to each other with no valve in the loop.

  • I have owned my 98 Explorer for 4 years, its a 6 cyl SOHV, not SOHC, 4X4.
    First problem: When driving with the a/c on and you accelerate, the air cuts out and blows hot air, but once the engine catches up with the idle, or you let your foot off the gas pedal it will begin to blow cold air again.
    Second problem started this winter: no heat... Originally it was a northern vehicle, so it originally had removed the thermostat, but when I moved south we reinstalled one. The truck will never get the temp gage more than 1/16" past the "C" from C to H, and now there is no heat coming out of the vents, but its too cold to tell if the a/c is working. Also, when you turn the knob from the blue "cold" area to the red "hot" area you do not hear the door opening or closing. I am not even sure you are supposed to hear it. You can however hear the vents change from foot/face/windshield settings

    Does anyone have a clue what could be the problem? I read up here about a "blend door", but have no clue what or where that would be, or how to check it.

    Thank you for anyone who can help. :sick:
  • I finally fixed my truck, it was the blend door actuater like everybody else. but I think that part that broke off was the reason y our motor broke. I have heat, but i still hear the banging noise as soon as i start the engine. I think that piece somehow regulated the vacum switch through the varies positions , and with no regulation the switch keeps putting mad presure on that actuater.But guess what i dont care, i wont worry about it until i dont have heat again. so get that regulater changed so your truck can be hot :shades:
  • Ford changed the HVAC system in 02 so a lot of the previous comments do not apply to your model. The earlier Explorer has the blend door on a vertical axis which is also susceptible to the same sorts of failure as the later models. The difference is that when the axle connector breaks, the door is free to swing back and forth. Bumps in the road, hard turns, acceleration, fan speed, and general gremlins can cause the door to shift position randomly.

    Check the heatertreater web site at for diagnostic information and pictures of the most common fail modes. The actuator motor is located on top of the plenum box and can be accessed through the glove box opening. The motor is frustrating to remove, but you need to do this and examine the connection to the blend door.

    This is a common problem and there are lots of suggestions and procedures to effect a repair. The HeaterTreater is not the cheapest, but is the easiest and is proven over hundreds of successfull installations. If you just want to fix it once and be done with it, we can help.

  • I know this is probably dumb to ask, but have you checked the level of your radiator fluid. I have a 2003 Dodge Ram and the radiator developed a leak, and when the level of anti-freeze was low it would not blow hot air when stopped, and it would start to overheat. So check that.
  • LHWLHW Posts: 1
    When accelerating or climbing a hill, especially when pulling my boat, the air flow from the HVAC vents (either fresh air or AC) stops. But, once I let my foot off the gas, the air flow slowly returns. Seems like the air bleed door is electronically closing whenever there is a load on the engine because you can still hear the blower working but no air is flowing thru the vents.
  • you have a vacuum leak somewhere, or there is a bad check valve.......
  • I may have the same no heat issue with my 02 Explorer. I've been off work following surgery so a dealer fix is out of the question.Can reply to:
  • ebaxebax Posts: 1
    I have a 2002 explorer with the deatc system.Usually when you turn the truck on everything goes back to the previous settings but now when you start the truck its all shut off and it resets itself to 75 degrees.This is very annoying.Not sure what this could be,and would be thankful for any ideas.The heat seems to be working fine just don't want this to become a bigger problem.
  • Your problem sounds like the common blend door problem on the early Explorer. The door is on a vertical axis and when it breaks, it can swing back and forth randomly giving heat or AC or nothing. The difference on acceleration is the force placed on the door swinging it one direction.

    You can check the operation by fully opening the glove box, removing the actuator motor on top of the plenum box and examining the blend door axle. Pictures of the common fail signature are available on the web site. There are several "free" fixes that mostly are worth what you pay for them. The solution on the web site is solid and proven over hundreds of vehicles and will resolve the problem once and for all.
  • My 2002 Ford Explorers heat will not work....It blows out air just fine, but its cold...when I turn the controller on heat, it makes a knocking sound and just keeps blowing out cold air. I was reading a few other problems and I may get it, but if someone could tell me how to fix it....that would be great!!!

  • Hi Hash penni... I have a 98 Explorer and have recently discovered that my A/C is stuck on... I took it in to get the Thermostat changed (which was bad by the way), only to have the repair man, who is a former Ford employee, explain to me that the blend door actuator has gone bad... In mine, he opened the glove box and dropped it, and behind it on the fire wall was a white box with a wire plugged in it.. he unplugged it and turned the air on and off and there was no change in the system.. He then informed me that the BLEND DOOR MOTOR... or what is further referred to at Autozone, Advance, and Pepboys as a blend door actuator is what I need to fix it...

    After further review, it has to be ordered (3-5 day wait) and the entire dash has to be removed to change it...

    Again, I do not know if this is your problem but its a place to start...

    Good luck ;)
  • I have a 2002. When I put on the front defrost, not much air comes out. Much of the air still comes out of the floor. Any ideas what could be causing this?
  • This thread has discussed both the old and newer plenum boxes. The pre 02 box is the easier to fix. As mentioned, you can fully open the glove box and view the actuator motor on top of the box. Ford didn't leave much room to work on the motor, but with a little patience, the motor can be removed. Figure on some scraped knuckles and a couple of censored comments to get the job done. Two attachment methods were used. One is just a plastic pinch connection and the motor can be removed by prying up with a large screw driver. Screws directly into the box were also used and the two front screws are easy, but the back one requires a very slim ratchet. Either way, with a box of bandaids and persistence the motor can be removed.

    Once the motor is off, you can feel the top of the axle or view it with a mirror. My favorite trick is to use a digital camera to "see" where I can't put my head. On this one, there's not even enough room for a camera. There are two common break patterns for the axle and examples and pictures are available on the HeaterTreater web site. Most of the time, you will find one of these fail modes and the diagnosis of a broke blend door(common) is fairly obvious.

    The trick now is replacing the blend door without having to remove the steering column, remove the dash, evacuate the AC, drain the radiator, and finally remove the plenum box. Replacing the blend door is easy, it's the work to remove and replace the dash that is difficult....and after you go to all that work, you are just putting in another plastic blend door that will break again over time. The good news is that the second time you will be experienced and it will take a little less time.

    There are various fixes for this problem ranging from a three cent nail inserted into the motor axle to paying the dealer $$$$$ to disassemble the Explorer and put in new OEM Ford approved plastic. The HeaterTreater fix cuts an opening in the bottom of the plenum box in the passenger side footwell and replaces the door with a metal replacement that will NOT have the same failure problems as the plastic door. You end up with metal duct tape sealing the bottom cut in the box and if you lay on your back and squeeze under the dash, it will look hacked. Fully functional, but hacked. The solution has been installed in hundreds of Explorer/Ranger/Mountaineer's with 100% success. This isn't the least expensive fix, but is a severe fraction of dealer cost and is proven to be a one time permanent solution. The engineers at HeaterTreater are the experts and you can rely on the fixes and customer support from that team to guarantee success on restoring HVAC function to your automobile. Check the web site( for full details of the fix and technical reports on different solutions.

    The newer box(02+) is a different animal and the fix is completely different. Again, check the technical information at HeaterTreater to understand, diagnose, and fix problems on this box as well as the earlier box.
  • I have a 97 explorer (4x4) 4.0efi , i went out and everything worked fine ... parked to like two hours and then used remote starter truck started no problem , need i say this was in a bad snow storm up here in ottawa canada. But when i went out to truck 5 minutes later i noticed the windows were not heat , no blowing air nadda everything is dead in the heating system ? checked everything from fuses to connections under dash to under hood fuses at total loss here not mechanically inclinded as the old saying goes any suggestions !!!!!
  • Thanks heatertreater. Just to be clear...from this thread it sounds like the common result of the blend door failure is no heat. In my case, the air gets plenty hot (or cold if using AC) it just doesn't adjust from defrost, to floor, to vents, etc. Are we talking about the same failure mode (blend door) which will have this result as well?
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