[W126 Coupe] Interior ACC vacuum & electrical repair notes

[Dick Spellman]

For anyone looking to do acc and other repairs to the interior of a 126 
chassis car here are the general steps needed (absent a passenger air 
bag) that I wrote for Markus who is tearing down a 300SE Euro 1986 and 
renovating as needed.

Just don't want to repeat the write up at some later date so here it is 
for archives, whatever.

Dick


> You have some actuators with dual diaphragms hence the additional 

> pieces.  My only instructions on there removal is to be sure and label 

> there positions prior to removal.  Note & mark which leg to the steel 

> arm has the locking notch and carefully release this using a pick, 

> then twist. Use a marker and/or a camera.  In dis-assembly of any one 

> pod, mark the outer casing, note the position of the linkage and be 

> careful in separating the pod pieces not to damage the clips.  Some 

> are two pieces and others (with 2 diaphragms) are 3 pieces.

>

> Mine as well remove the knee bolsters on both sides and the front 

> console side carpet pieces and the glove box.  Then everything is 

> accessible.  If you are doing the seats at the same time, just pull 

> them out and you'll have a bit more room to work around in the dash.  

> If the seats are removed, mine as well pull the entire console between 

> the seats for total access.  Then you can clean, inspect, re-wire 

> radios, speakers, cell phone, satellite and any needed auxiliary power 

> outlets, replace bulbs, repair any rubber that's cracked in the lower 

> shift selector area, etc.  Once everything is out of the way, it's 

> really very easy to work on each repair until all known issues have 

> been cleared.  Your instrument cluster needed some work too from 

> fading, probably do the clock while you have this out, replace all 

> bulbs, etc.

>

> Re: the actuators, just mark each piece up, re-assemble to George's 

> instructions and you should be fine.  You will know if you messed up 

> because it's easy to pierce those new rubber pieces if you are not 

> careful.  I test each one with a mightyvac to 7-10 inches and make 

> sure they do not have slow leaks before planting them back in the 

> car.  I would test each vacuum line off of the switching valve once 

> the rebuilt actuators are reinstalled and observe the linkages 

> movement etc.  Here you may move the mightyvac to 13-14 inches.  

> Don't  apply more than this as you could damage the rubber.  Pretty 

> sure the system works on 15-17 but, just apply what you need to see 

> things are working as they should.

>

> Final test of the ACC will be to run the system and be sure the 

> pushbutton unit is managing the vent directions and outputs per the 

> Mercedes Manual. The blower is cycling as it should.  Clean-up the 

> aspirator sampling motor down to the right of the glove box opening 

> and test the line to the inlet up at the roof control switch.  If 

> everything checks out, put the car back together again. That's about it.