Thanks
Air Mix Servo???
Thread Starter
Rookie
Joined: Feb 2007
Posts: 98
Likes: 2
From: AZ
Air Mix Servo???
Has anyone heard of this air mix servo. I have a ticking sound around the passenger dash by the glovebox. I was reading a thread that this guy took it to Lexus and they changed this? Where is it and is that the actual name b/c i have not found one online for it??? Thanks for the help. You only hear the noise when the radio is off and windows up, car running.
Out of Warranty
Joined: Aug 2001
Posts: 14,925
Likes: 13
From: Houston, Republic of Texas
A while back someone reported a similar problem and Tracilex over on the LOC forum had an answer. Apologies, I am not able to make the link work, so here is his fix.
Thanks to Tracilex and the Lexus Owners' Club!
I think I've got this one licked...
The noise is coming from the servo motor that moves the door for the "mode" button. This servo moves diverters to change from vent to floor, etc.
- I popped the bottom panel off under the glove box.
- I then removed the glove box assembly. 2 screws up high, 2 bolts down low.
- With the key on engine off you can press the mode button and watch the servo move. Turn the key completely off.
- Remove 3 screws and plug to take the assembly out.
- Do not attempt to rotate the arm on the end of the servo. It engages w/ a worm gear. Turn it and you will break gears.
- The servo is a snap together unit. Carefully take it apart w/ the arm side down.(so gears don't fall out)
- inside you will see multiple wiper fingers that make contact w/ a gear. Carefully clean these w/ alcohol and a cotton swab.
- Redistribute the contact grease on the wiper pad w/ a clean finger (any oil or lotions on skin will mix w/ the grease and make the copper contacts corrode.
- Carefully snap unit back together.
- Clean contacts on the outer part of servo also w/ alcohol.
The other option is to have Lexus diagnose this for you and hit you for $160 for the part plus ~ an hour or 2 labor.
So far the noise is gone and the HVAC system works properly. I will post any updates if the problem comes back. I think the problem was caused by crusty contacts in the servo that were creating a poor signal back to the computer that controls it. Now that it has a clean signal, all is well..... I hope!!!
The noise is coming from the servo motor that moves the door for the "mode" button. This servo moves diverters to change from vent to floor, etc.
- I popped the bottom panel off under the glove box.
- I then removed the glove box assembly. 2 screws up high, 2 bolts down low.
- With the key on engine off you can press the mode button and watch the servo move. Turn the key completely off.
- Remove 3 screws and plug to take the assembly out.
- Do not attempt to rotate the arm on the end of the servo. It engages w/ a worm gear. Turn it and you will break gears.
- The servo is a snap together unit. Carefully take it apart w/ the arm side down.(so gears don't fall out)
- inside you will see multiple wiper fingers that make contact w/ a gear. Carefully clean these w/ alcohol and a cotton swab.
- Redistribute the contact grease on the wiper pad w/ a clean finger (any oil or lotions on skin will mix w/ the grease and make the copper contacts corrode.
- Carefully snap unit back together.
- Clean contacts on the outer part of servo also w/ alcohol.
The other option is to have Lexus diagnose this for you and hit you for $160 for the part plus ~ an hour or 2 labor.
So far the noise is gone and the HVAC system works properly. I will post any updates if the problem comes back. I think the problem was caused by crusty contacts in the servo that were creating a poor signal back to the computer that controls it. Now that it has a clean signal, all is well..... I hope!!!
Driver School Candidate
Joined: May 2004
Posts: 42
Likes: 0
From: Maryland
does anyone know the part# for the air mix servo? Any online store I can get this from? I've had no luck finding one.
My servo has gone bad and I've tried several times to clean the contacts and apply connector grease, but it still makes the buzzing sound only when the air flow is positioned to your head. It buzzes for about 10 seconds (really loud) then goes away. All other settings make no noise.
The dealer wants $180 for the part and I've tried junkyards who believe it or not want $250 - $300 for a used part because of "the labor included in pulling the part". I've even tried to Toyota dealer to see if the highlander uses the same motor and while they could not confirm that for me, the price was the same at $180.
My servo has gone bad and I've tried several times to clean the contacts and apply connector grease, but it still makes the buzzing sound only when the air flow is positioned to your head. It buzzes for about 10 seconds (really loud) then goes away. All other settings make no noise.
The dealer wants $180 for the part and I've tried junkyards who believe it or not want $250 - $300 for a used part because of "the labor included in pulling the part". I've even tried to Toyota dealer to see if the highlander uses the same motor and while they could not confirm that for me, the price was the same at $180.
CL Community Team
Joined: Apr 2001
Posts: 16,595
Likes: 1,400
From: Austin, TX
call local Lexus dealership and talk to the parts people for the part number. They even fax out components assembly (which can be helpful if you dont have the service manual).
As far as servo is concerned, you are pretty much locked in with Lexus. Just save on labor and make your summer comfortable.
Salim
As far as servo is concerned, you are pretty much locked in with Lexus. Just save on labor and make your summer comfortable.
Salim
Driver School Candidate
Joined: May 2004
Posts: 42
Likes: 0
From: Maryland
the parts people wouldn't give me the part number and I've had no luck with searching on the net. I really hate to pay $180 for a part that probably cost them less than $30 to manufacture, but unless anyone has any other options, i'll probably have to just bite the bullet.
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CL Community Team
Joined: Apr 2001
Posts: 16,595
Likes: 1,400
From: Austin, TX
this only 1/2 the story
More on servo:
There are 2 servos in the passenger foot-well.
One is fairly obvious once you take the glove compartment off. ... in the foot-well but on the side of the gear shift pod. 2 screws are clearly visible on this but the third (one closest to the firewall) is accessible with stubby Phillips but one has to work blind.
The second servo is few inches away ... more closer to the feet and towards the firewall. Once again the screw closet to the firewall is not visible. BUT the top screw is visible, but is not accessible. The refrigerant lines run right in front of the screw.
Salim
There are 2 servos in the passenger foot-well.
One is fairly obvious once you take the glove compartment off. ... in the foot-well but on the side of the gear shift pod. 2 screws are clearly visible on this but the third (one closest to the firewall) is accessible with stubby Phillips but one has to work blind.
The second servo is few inches away ... more closer to the feet and towards the firewall. Once again the screw closet to the firewall is not visible. BUT the top screw is visible, but is not accessible. The refrigerant lines run right in front of the screw.
Salim
Driver School Candidate
Joined: May 2004
Posts: 42
Likes: 0
From: Maryland
thanks. I will try searching by part number. My issue is definitely with the air mix servo. here is what happens:
There is a really loud buzzing sound only when the servo is positioned so that air is blowing at your head. The buzz goes away after about 10 seconds. And, I tested the head position with the servo not connected to the arm that moves the flow of air and there is no buzz. Could not figure out why the servo box vibrates and makes the buzzing sound when it was connected to the arm. Nothing is loose under there.
Has anyone else ever experienced this? Also, what type of connector grease is everyone using on this? I went to Advance and tried their electrical connector grease and bulb grease, but i noticed that they were both not as thick as the grease from the factory.
There is a really loud buzzing sound only when the servo is positioned so that air is blowing at your head. The buzz goes away after about 10 seconds. And, I tested the head position with the servo not connected to the arm that moves the flow of air and there is no buzz. Could not figure out why the servo box vibrates and makes the buzzing sound when it was connected to the arm. Nothing is loose under there.
Has anyone else ever experienced this? Also, what type of connector grease is everyone using on this? I went to Advance and tried their electrical connector grease and bulb grease, but i noticed that they were both not as thick as the grease from the factory.
Driver School Candidate
Joined: Sep 2007
Posts: 2
Likes: 0
From: Mn
I would like to gain access to the air/mix servos to see if cleaning them fixes the problem...or at least know that I would be able to replace the part myself.
However, I was unable to remove the glove box. I removed the two screws on top and two bolts on the bottom, but the box is still stuck along the top near the latch cutout. I am hesitant to force it because i don't want to break anything. Is there a hidden screw...or is there a special technique to get it to come loose? Thanks, Joe
However, I was unable to remove the glove box. I removed the two screws on top and two bolts on the bottom, but the box is still stuck along the top near the latch cutout. I am hesitant to force it because i don't want to break anything. Is there a hidden screw...or is there a special technique to get it to come loose? Thanks, Joe
CL Community Team
Joined: Apr 2001
Posts: 16,595
Likes: 1,400
From: Austin, TX
Drop the bottom panel down from the front and pull out. It is only held by clips.
You can also pull out the kick plate (one large plastic screw head .. really is a pop out) that wraps the gear shift pod [passenger side way below and near the fire wall).
The Glove box is held by four screws and some glue (near the top edge ... near cd loader slot). Just give enough force to separate but not pull way apart as the courtesy light in the glove compartment is attached to the glove box. Once separated gently undo the wire clamps and remove the assembly without separating the connectors.
Be very careful when you remove the screws on the servo. I dropped one behind the center console and needed my wifes slender hands to retrieve it.
Also do not attempt to disassmble without a stubby phillips.
Last tip the air duct from the center console to the passenger calf area may have to be removed to gain access. The screw that holds it in place from the center console need not be removed .[just loosen it enough as the duct has a slot .. then again it is not a biggie if you totally remove it].
Salim
You can also pull out the kick plate (one large plastic screw head .. really is a pop out) that wraps the gear shift pod [passenger side way below and near the fire wall).
The Glove box is held by four screws and some glue (near the top edge ... near cd loader slot). Just give enough force to separate but not pull way apart as the courtesy light in the glove compartment is attached to the glove box. Once separated gently undo the wire clamps and remove the assembly without separating the connectors.
Be very careful when you remove the screws on the servo. I dropped one behind the center console and needed my wifes slender hands to retrieve it.
Also do not attempt to disassmble without a stubby phillips.
Last tip the air duct from the center console to the passenger calf area may have to be removed to gain access. The screw that holds it in place from the center console need not be removed .[just loosen it enough as the duct has a slot .. then again it is not a biggie if you totally remove it].
Salim
Driver School Candidate
Joined: Apr 2008
Posts: 9
Likes: 3
From: NY
I have the same problem that most of you have with the servo motors. I pulled the glove box off and found the Air mix motor rotating back and forth. Pulled on the plug going to the motor and it stopped.
So it's a definite contact problem between the plug and the aix mix servo. I would think the Vent servo motor would have the same issue.
I pulled the motor and cleaned the contacts. For me, there was no need to open up the motor.
Hope this helps
So it's a definite contact problem between the plug and the aix mix servo. I would think the Vent servo motor would have the same issue.
I pulled the motor and cleaned the contacts. For me, there was no need to open up the motor.
Hope this helps
Rookie
Joined: Apr 2008
Posts: 88
Likes: 1
From: SC
Yeah I had the same problem with the Air Supply Mixture servo on my 99 a few weeks ago. I figured out which servo was causing the noise and went to Lexus they told me 160.00 for the part which made me laugh. I noted that the position of the lever making the ticking sound was not correct. I took out the servo (was going to be replaced one way or another) and disassembled it. It has like 6 or so plastic tabs holding it together. I turned the lever assembly on the servo to the correct bottom position re-assembled it, and re-installedi it. Works like a champ and no problems. I don't know how the lever got so far out of position but it did. If before you remove the servo from the car (with the car off) you can operate the track that the servo lever feeds into it will help you determine the correct position of the lever. It only takes about 1-1/2 hours to complete this repair total. Hope this helps, if needed I can take some pictures and post them if needed.