Motsbro
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- October 19, 2015
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- Year, Model & Trim Level
- 2000 Mercury Mountaineer
Fixed Blend Door Problem!
Chiming in here with some tips following my adventure fixing the blend door actuator. I have a 2000 Mountaineer with Automatic AC (EATC - basically you set a thermostat type temperature). What follows are an immediate work around, and permanent fix.
Quick Manual work around. This is a fairly quick job (less than an hour) that will get you working heat and AC up and running. My blend door was OK (sometimes the hinges crack apart) but my actuator (the motor that moves the blend door) failed. If you don't have a replacement actuator, you can still get things working. After searching the web I found an explorer forum that showed how to access the blend door by cutting into the black plastic duct work in the passenger foot area. . . .not as bad as you'd think . . . Check it out for details and pictures but here's the summary of my experience. Looking under the dash on the passenger side (head on the floor . . not comfortable) you can see black duct work. About the area above where your passenger's left foot would be is a fairly flat are of the duct. Look for a raised round area (a bit smaller than a dime but about a 1/4 inch tall). This is where the blend door pivots. Using a cheap rotary tool with a cut off blade I cut out a couple-inch or so triangular area beside (but NOT including) the hinge's raised area. The area I cut out was within the small flat area beside the door hinge. Once open, I could touch the blend door, moving it one way or the other with my fingers (after the actuator was removed). During the summer I wedged it in the cooling position, and vice versa in the winter. You'll need to close the hole up for the air to pass through your ducts instead of the new opening. Using one of those black plastic covers for an electric box, I fashioned a door (cutting it with the rotary tool, about a 1/4 inch larger than the whole I made), added some weather seal and screwed it into place. The fix can't been seen since it under the dash . . . unless you put your head on the floor. I lived with this solution through two years of procrastination/searching for the right actuator.
Permanent fix. The blend door for automatic systems are different from the manual systems. They look similar or even identical on the outside but internally have a different circuit boards. Also, the automatic Actuators I found on line and at auto parts stores did not work on my older system (2000) so I found one as a junk yard. (On further thought they might have worked but at the time I didn't know about the EATC reset procedure described below . . .crap!). The Blend door actuator is a pain to get out. The back screw requires a lot of patience but completely doable. I didn't bother to put the back screw back on for my replacement. Aligning the post that sticks out of the actuator (about an inch) with the blend door hinge is a bit tough too. 2 things seem to be required. 1. The actuator needs to be near horizontal (not tilted) position. What worked for me was I put in the front left screw a couple turns and then stuck a screw drive under the left side of the actuator to prop it up. 2. The post that sticks out of the actuator needs to be aligned with the hold in the blend door hinge as is has a unique shape (round on one end, flat on three sides). With the access door open (see my work around in the paragraph above), I could move the door around until the actuator dropped into place. Once in, I replaced only the front two screws and it works fine. If you don't do the access door to help with alignment, you can use a cell phone to take an image of the opening to see its position, then using your ac controls, move the post into the proper position (basically get it to move by plugging in the wire harness to the new actuator, switching your ac controls between ac and heat and then pull the plug on the actuator when the post reaches the correct position. If it doesn't move, use the procedure in the next paragraph to reset your EATC system. If it doesn't move after resetting, you either have the wrong actuator (a good possibility) or something else is wrong, such as a fuse or ac control panel problem.
Resetting EATC. If you have an automatic temperate control (EATC), not the manual system, you will likely need to run a diagnostic test and then clear the fault code(s) on your temperature control system. (EATC systems have a digital display of temperature settings and several buttons while Manual systems have just knobs, I think). With Car power ON and AC OFF, press Off and Floor (at the same time) and then press Automatic within 2 seconds. It will take a couple minutes to run the test. When done it will display any fault codes. To clear codes and reset the system, press Def (defrost) after the diagnostics has run. Good Luck!
Chiming in here with some tips following my adventure fixing the blend door actuator. I have a 2000 Mountaineer with Automatic AC (EATC - basically you set a thermostat type temperature). What follows are an immediate work around, and permanent fix.
Quick Manual work around. This is a fairly quick job (less than an hour) that will get you working heat and AC up and running. My blend door was OK (sometimes the hinges crack apart) but my actuator (the motor that moves the blend door) failed. If you don't have a replacement actuator, you can still get things working. After searching the web I found an explorer forum that showed how to access the blend door by cutting into the black plastic duct work in the passenger foot area. . . .not as bad as you'd think . . . Check it out for details and pictures but here's the summary of my experience. Looking under the dash on the passenger side (head on the floor . . not comfortable) you can see black duct work. About the area above where your passenger's left foot would be is a fairly flat are of the duct. Look for a raised round area (a bit smaller than a dime but about a 1/4 inch tall). This is where the blend door pivots. Using a cheap rotary tool with a cut off blade I cut out a couple-inch or so triangular area beside (but NOT including) the hinge's raised area. The area I cut out was within the small flat area beside the door hinge. Once open, I could touch the blend door, moving it one way or the other with my fingers (after the actuator was removed). During the summer I wedged it in the cooling position, and vice versa in the winter. You'll need to close the hole up for the air to pass through your ducts instead of the new opening. Using one of those black plastic covers for an electric box, I fashioned a door (cutting it with the rotary tool, about a 1/4 inch larger than the whole I made), added some weather seal and screwed it into place. The fix can't been seen since it under the dash . . . unless you put your head on the floor. I lived with this solution through two years of procrastination/searching for the right actuator.
Permanent fix. The blend door for automatic systems are different from the manual systems. They look similar or even identical on the outside but internally have a different circuit boards. Also, the automatic Actuators I found on line and at auto parts stores did not work on my older system (2000) so I found one as a junk yard. (On further thought they might have worked but at the time I didn't know about the EATC reset procedure described below . . .crap!). The Blend door actuator is a pain to get out. The back screw requires a lot of patience but completely doable. I didn't bother to put the back screw back on for my replacement. Aligning the post that sticks out of the actuator (about an inch) with the blend door hinge is a bit tough too. 2 things seem to be required. 1. The actuator needs to be near horizontal (not tilted) position. What worked for me was I put in the front left screw a couple turns and then stuck a screw drive under the left side of the actuator to prop it up. 2. The post that sticks out of the actuator needs to be aligned with the hold in the blend door hinge as is has a unique shape (round on one end, flat on three sides). With the access door open (see my work around in the paragraph above), I could move the door around until the actuator dropped into place. Once in, I replaced only the front two screws and it works fine. If you don't do the access door to help with alignment, you can use a cell phone to take an image of the opening to see its position, then using your ac controls, move the post into the proper position (basically get it to move by plugging in the wire harness to the new actuator, switching your ac controls between ac and heat and then pull the plug on the actuator when the post reaches the correct position. If it doesn't move, use the procedure in the next paragraph to reset your EATC system. If it doesn't move after resetting, you either have the wrong actuator (a good possibility) or something else is wrong, such as a fuse or ac control panel problem.
Resetting EATC. If you have an automatic temperate control (EATC), not the manual system, you will likely need to run a diagnostic test and then clear the fault code(s) on your temperature control system. (EATC systems have a digital display of temperature settings and several buttons while Manual systems have just knobs, I think). With Car power ON and AC OFF, press Off and Floor (at the same time) and then press Automatic within 2 seconds. It will take a couple minutes to run the test. When done it will display any fault codes. To clear codes and reset the system, press Def (defrost) after the diagnostics has run. Good Luck!
