06 Air Mix Servo Stuck/No heat/SOLVED.

2006 Tacoma No Heat, Air Mix Servo Repair


Just wanted to post this as I want able to find much info when I needed it.

Started my truck on about the first cold morning and 0 heat all the way to work, fan blew as normal just no heat at all. I was stumped as I have had my truck 10 years and never a single issue. Coolant level good, both heater core tubes going through the firewall were hot so I could rule out a blockage in the heater core and thermostat was working.

Next I moved into the cab to check if there was an electrical issue or bad servo that controls the air mix. I found another thread stating the hvac servos are in passenger side foot well so I removed the glove box and poked around a bit. There is a servo immediately visible when removing the glove box but this is not the air mix servo, this servo controls which vents the air is directed I believe. You can turn the ignition on and listen carefully while moving the temp dial and vent selection dial for the servos moving, my first idicator the air mix servo was not working was I could not hear the servo moving at all when changing the dial from hot to cold.

It turns out the air mix servo is located right behind the passeneger side foot air duct, shown in the picture below it can be easily removed with a gentle tug and a few wiggles, there are only a few pressure clips holding it in place. Once the passenger duct is removed you can clearly see the air mix servo.


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At this point after locating the air mix servo I tested the controls changing the dial from heat to cool and there was no movement in the servo or actuator arm. I removed the servo wiring harness and with a socket, only 2 screws hold the servo in place and can easily be removed. Next I opened the casing of the servo which is only held together by clips, inspected all gears and was surprised there was no stripped or broken gears and everything appeared in working order. At this point with the casing still open I hooked the servo back up to the wiring harness and checked while moving the temperature dial (with ignition on) and the servo was working perfectly.





After verifying the servo was working I checked the actual lever mechanism the servo controls shown below



The full range of the servos movement from cold to hot is only about 1/2 a revolution so when I attempted to turn the lever mechanism shown above by hand it would not move at all. Somehow this mechanism became jammed in the coldest position. After manipulating it by hand I was able to unjam the mechanism and move it by hand from hot to cold freely and smoothly.

At this point I started the truck and got it nice and warm and was able to verify free flowing hot air. Now it is just reattaching the servo to the mechanism, snapping the air duct back in place and re attaching the glove box.

This whole process took me about 15 minutes, and I had little idea of what I was doing, I had never even removed my glove box before. I was a little nervous seeing other members stating the dealership charged $900-1000 to fix this same air mix servo and claimed they "had to tear down the whole dash", even if the servo is broken they can be picked up for around $90. Hopefully this helps someone out in the future!

 

I'm having the same issue as you....but i can't get the side foot air duct off at all.

 

I'm having this issue now. The part number is 87106-04050, currently no aftermarket part.

 

I replaced the part, still partial travel- I may not have installed it with the door or servo in the proper position. I will verify installation tomorrow and check the door for freedom of movement. The next step after that is verifying the servo is receiving proper voltage. I should have checked both of these things BEFORE replacing the part.

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Nice writeup! Thank you for sharing!

 

So there was nothing wrong with my servo, I had put a 2015 ac/heater control into my 2005 and one of my solders came loose. I repaired the soldered wire and everything works as new.

 

Good info! Nice write up.

 

Did you do that swap for the facia color or a different reason?

 

I know this is an old thread. But great write up and photos!! Great info to know!

 

Cosmetic, I thought the black looked better than the silver

 

Yeah me too. Did it have a different wiring plug?

 

Yes, there's a writeup or two on TW

 

An actuator started clicking
Then stopped
Apparently there’s 3.

then air stopped flowing. I think the door is stuck closed. Is this the one?

already pulled the actuator apart. Going to put it back in.

question is, the actuator obviously has end stops. What about the door it attaches to with the keyed slot?
Want to make sure I don’t put it on backwards or something

guess I can trial and error it. If one way doesn’t work pull it back apart and re install it the other way. Then see what happens. Doesn’t take long.