Center Vents not working...Yes, I know this is a common problem

[RickM]

After operating the A/C I realized the center vents do not function on my 1985 380sl.

Did a search on this subject and found it to be a common problem. Unfortunately, the info is mostly for other models.
What I have learned is the following:

- The vents are operated by vacuum via an actuator.

- The defrost vents and center dash vents may be related in operation...each with there own actuator.

- The actuators can be labor intensive to get to. But I don't know where they are on the 380sl.

- Actuators can be expensive, however, if the diaphram is the culprit thre are sources to buy this part seperately.

- Problem may also be vacuum supply to the actuator(s).


Questions:

-Can anyone direct me to the location of the center vent and/or defrost actuator and perhaps an idea of how to get to it?

-Any other obvious components to consider?

-Is there a vacuum diagram available on the net?


Any and all help is appreciated!

[PCM84]

If anyone has their dash currently disassembled, I would love to see the location of these actuators, etc. I've found photo's of how to change my antenna on this forum... anybody have a dash disassembled?

[ctaylor738]

Aren't they all in a row just behind the glove box? I had the glove box out to test the fan relay and they certainly looked like vacuum actuators.

I just replaced my defrost vent actuator on my 86 560sl. It can be a ***** to get to, I had to remove the console to get to it. The acuator is on the left upper side of the radio. it is a dual acuator that can be removed and repaired or replaced. it has three wiz nuts holding it on the bracket, I broke the actuator removing it. I bought the acuator for my 86 about a year ago and had read that you have remove the dash to service it. to install a new one you have to remove the wiz nuts to get it out or take it apart to replace the diaphram.

86 560sl
94 Chev S10

[seacoast_benz]

I can't recall if the actuators can be gotten to via the glove box opening, but the GB on a 107 car is so easy to take out that it is worth a try. Four pop-fasteners, piece of cake!

I found one center vent inop because the hosework was off. Easy fix.

s/b

[RickM]

Here's a place to buy the diaphrams and tools for the actuators....along with some interesting and inexpensive solutions for other problems. http://www.autoluxmbz.com/

Can someone post directions for getting to the actuator which controls the center vent? If it's a nightmare to get to I may just fix the vent in an "always open" position. BTW, I'll be replacing the radio shortly so this may be a good time to attempt the actuator/vacuum troubleshooting.

Rick,
The 107 maintenance manual says to remove the dash to service the actuator, DON"T DO IT. You can get to the actuator thru the center dash openig if you remove the climate control unit, radio and console it is on the upper left of the opening there is a rivet holding the arm to the top of the actuator this has to be drilled out, I used a #10 drill bit. if you get the parts and the tool to disasemble the actuator the new diaphragm should be a snap to change. On my 560 it is a dual actuator so you have two pieces to remove. Make sure the new actuator is seated properly or you will be back where you started. You will have to use a machine screw w/ locknut or a rivet to hold the arm on the actuator, don't over tighten or it may bind up. Putting everything back together is a snap. I did mine last week, so if you need any guidance let me know.
Good Luck
Frank

86 560SL
94 Blazer S10