Changed Blend, Mode & Recirculation Accuators - Ouch! Oh & HOW TO
What I'm saying is that I'll never do that again. It took a solid day to change these three things in my '99 Trep. Now I have scrapes, bruises and various red spots up and down my forearms. I know people said how tight it was to get back underneath where the blend and mode door accuators are, but it's done!
All my stuff works now! Sweet! No clicks, no turning it off and on and off and on and off and on to get heat.
OK, my rant is over. But thankfully it's done.
P.S. I bought a ratcheting 5/16th's wrench to get the screws back on. Wish I had bought it before I took the screws off, would've been much easier. I HIGHLY recommend that anyone attempting this use this ratcheting wrench.
Here is a picture of the ratcheting wrench set I bought in order to use the 5/16ths wrench. It was very, very tight above the transmission hump. I'd still be doing it if I didn't pick up this wrench!
BTW, I tested many different ratchet wrench kits. I was really looking for a ratchet that was not very hard to turn at all. You know how it is when you start these kinds of screws, too hard for your fingers to turn but not enough resistance to cause the ratchet to click so it spins back and forth with the ratchet. This particular kit of wrenches had a very soft and easy ratchet that had very little resistance. Essentially, once I get the screw started as far as my fingers could, the ratchet really could take over without just spinning the screw.
This kit was $39.95 at Sears.
Originally Posted by cdmccul
Great news!! Congrats! What kind of ratcheting wrench - like a combination wrench, or like a ratchetting screwdriver?
<------- This guy would love to have a description and a how-to. i dont even know what the mode door actuator looks like. i just know where it is and i dont want to spend all day trying to figure it out.
OK, so here are the codes I had
HVAC codes come up
23: Blend door actuator feedback failure (bad servo)
31: Recirculation door actuator stalled (stuck door or bad servo)
I didn't know much about these before hand except that a couple of years ago I had the shop do the blend door actuator for me it to the tune of about $600. I did not want to spend that money again. So planned on doing it myself.
My original symptoms were a clicking noise coming from the right side of the dash behind the glove box again, to the right of it. I did not have consistent heat nor consistent A/C. I had to turn off and on the fan or turn the temperature selector back and forth between cool and warm to get it to do what I wanted. I did the A/C code check on got the above codes.
Since I didn't know much about them, I did some research here and found similar symptoms and decided to tackle it myself.
There is also a Mode Door Actuator that looks nearly identical in shape to the blend door and is a little easier to get to. The primary difference in appearance is that the blend door has a white, almost see thru cover where as the mode door is all black. Don't try to install one for the other. You'll get 2 screws in and realize that the third is slightly offset and will not fit.
So here it goes:
1. Remove the shifter handle, requires a small allen wrench.
2. Remove both of the side console covers and the shifter cover.
3. Remove the glove box (4 screws on the bottom of the hinge).
4. Remove all of the dash covers below the dash pad.
5. Remove the 3 pieces of ductwork.
5.a. One piece under the steering column (1 Phillip's screw near parking brake release lever)
5.b. One piece below the glove box (1 plastic push pin rivet)
5.c. Behind and below the stereo (2 screws, use a 1/4" drive deep well 5/16" socket)
6. Optional, remove stereo & storage cup below stereo (6 Phillip's screws total)
6.a. It's easy, so I did this for better visibility and once or twice needed a better angle to screw/unscrew.
First the easy one: recirculation door actuator
Look behind where the glove box was and to the right, right next to the computer. There are 3 screws holding this actuator in place. You'll see that it also has a slide connector that is positioned only by mounting the actuator itself and is not directly connected to the car.
1. Remove the lower 2 screws (5/16th) using a ratcheting wrench. I found it easier to lay across the driver's seat, reaching across the passenger foot well to unscrew the screws. Just was a better angle for my hands.
2. Turn the actuator towards the firewall. It will be loose enough at this point to disconnect the slide pin as well.
3. With the actuator slid towards the front of the car, use the wrench to remove the 3rd and final screw.
4. Unplug the electrical connector.
5. Replace it with the new actuator in the reverse order. **MAKE SURE TO PLUG IN THE ELECTRICAL CONNECTOR PRIOR TO SCREWING IN THE NEW ACTUATOR. You won't be able to plug it in after. Ask me why I know this.
6. Temporarily plug in your temperature controls.
Second, the Mode Door Actuator
This is located right behind and below where the plastic cup below the radio is. There are 3 screws holding it in and 1 electrical connection. It is about 4" across and has a black cover.
1. Unplug the electrical connection. Note how the wiring is located around the center duct.
2. From the passenger side, using the 5/16th" ratcheting wrench unscrew the 2 nearest screws ( right screw & rear screw)
3. From the driver side unscrew the last screw.
Do not continue this section if you are also installing the Blend door actuator. Complete the third section then continue here once it is installed.
4. Plug in the electrical connector.
5. Place the new actuator in place. If the holes don't line up with the keyed pin in place, pull it out slightly leaving the keyed pin in the keyed hole and turn the actuator until it does line up. Go slow as to not over rotate.
Third and hardest, the Blend Door Actuator.
This actuator looks identical to the Mode door actuator except that it has a white cover AND the 3 mounting holes are slightly, differently positioned. It is directly behind (closer to the firewall) and slightly higher than the Mode Door Actuator.
1. Remove the push pin plastic rivet that holds down the small center ductwork that connects to the 'Y' duct that goes around the shifter.
1.a. Slide the duct towards the rear of the car, only enough to slide the front end off of the hole flange.
1.b. Jimmy the piece of duct out of the way towards the passenger side.
2. Using the 5/16th's inch ratcheting wrench unscrew the 2 screws nearest the passenger side. Do this from the passenger side. The rear screw is the hardest and tightest spot of the whole job. The ratchet wrench is vital here. I don't believe I could have replaced this screw without it.
3. From the driver's side, unscrew the last screw.
4. Remove the actuator.
5. Unplug the electrical connector.
6. Plug in the electrical connector to the NEW actuator.
7. Plug in the new actuator.
7.a. If the screw holes don't line up, lower it slightly so that the keyed pin is in place.
7.b. Rotate the actuator slowly until the screw holes line up. This can be tricky so be patient and go slow.
8. Reverse order, replace the screws. The ratchet wrench is a life saver here.
10. CAREFULLY, reinstall the center duct. Note the wiring to the front Mode Door Actuator.
10.a. Slide the male end into the 'Y' duct. Slide it as far in, past the retaining notch.
10.b. It is important to slide the front end completely around the hole flange for this. It is very frustrating, but can be done. You can stick your fingers behind to ensure that the duct is completely around the flange and not crimped under or inside it. Again, go slow and be patient.
11. Put the push pin rivet back in.
12. Continue to #4 in the Mode Door install
Once all the actuators test ok, reverse order the dash panels and voila! It's done. It took me the better part of a day to do all 3 of these. This amount of time did include me running to Sears to get a ratcheting wrench. Again, make sure you have a low resistance wrench so that you don't just turn your screws both ways because the screw isn't tight enough engage the ratchet.
Most important I believe is to be patient. You're working with very tight spaces. It's very easy to get frustrated. The work is not complicated, only tedious.
Last edited by rleeds; 02-21-2011 at 05:22 PM..
My original symptoms were a clicking noise coming from the right side of the dash behind the glove box again, to the right of it. I did not have consistent heat nor consistent A/C. I had to turn off and on the fan or turn the temperature selector back and forth between cool and warm to get it to do what I wanted. I did the A/C code check and got the above codes.
When you say "I did not have consistent heat nor consistent A/C.", do you mean your HVAC would occasionally send out heat when you were running A/C and occasionally send out A/C when you wanted heat?
Mine does that and I'm trying to figure out the best approach to fixing it.
Have you had any issues since you replaced all 3 actuators?