Replacing Climate Control Buttons

[SLeazy Rider]

I ordered several replacement buttons for the climate control system in my '87 560 SL (like the "off" button and "compressor" button). They have arrived, and now I need some simple advice regarding how to switch them out. Assume I know nothing about car repair/restoration (which is not far from the truth). How do I remove the old buttons and replace with the new? Do I need any special tools to remove the old buttons or can I just pull them out with my fingers? I don't want to apply undue pressure and mess something up.

Also, I will soon receive a new "automatic blower" button as well (the thin white button on the right hand side); it was on back-order. The original of that one is completely missing. Once I receive the replacement, will it just slide into the empty slot?

Finally, I ordered and received a replacement "fresh air knob," which controls the flow of air from the side vent (it's really not a knob at all, but the little black rectangle that is used to open or close the A/C-heat vent). Do I just glue it on and, if so, what type/brand of glue do you recommend?

Thanks in advance for any help.

Glenn (aka "SLeazy Rider")

[David Langsam]

I spent hours on this. I took the whole thing apart, removing the climate control unit from the car, then took that apart. But I could not figure out how the buttons came off. Then I realized you just pull. You can do it right in the car without removing the climate control unit at all. I was pissed, but now I can feel better if you don't have to go through it. If you can't get a grip, you might try pliers.

I have no idea about the 'autom' button. Might be the same way. I remember there are little 'light bars' in the unit that guide light from a bulb to where the button is. You might have to be careful not to dislodge those. It's been a while, so I can't quite remember.

I have no idea about the 'fresh air knob'. My suspicion is that it slides off to one side. I find that Mercedes did not use glue for things that you might have to disassemble to replace other parts. For instance, the driver's side view mirror knob is a two piece contraption that holds it in place without any glue.

Good luck. David.

[Strife]

I think you should be able to pop them off with two pocket stainless steel rulers levered in on either side without marring anything. BTW, I found that just thoroughly cleaning human grime off my CC buttons made them look (and light up) like new, after replacing the bulbs - no replacement required.

[Walrus]

Just as recently as last night, I had my controller out of the car and on my workbench. The buttons "snap" onto a small stem that makes up the activating element of the switch itself. It took considerable force to remove the buttons. I used a 1/4" wide blade behind the buttons. The access was granted by unclipping the plastic frame of the controller first. This could only be done by removing the controller from the car.

Now, don't be discouraged, it is not that hard: however, it is also not necessary in your case to remove the controller. If you are not worried about damaging the existing buttons, simply grasp them with pliers and steadily pull. They will release, but you will feel like you are about to break something at any time (trust me, even with the unit on my workbench and visibility excellent, I was concerned). Once the buttons are extracted, replacement is simply "push them on". They will snap in place. The Autom button is exactly the same. Simply guide it into the slot, and gentlly feel to make sure the switch engages the hole in the button, then push. You will feel it snap onto the switch stem.

Now for a couple of caveats... The controller is mounted to the wood panel by two, small phillips screws, screwed into two small wood blocks which are glued to the backside of the dash panel. These have been known to break loose quite easily... Mine did that in fact, and I reglued them with 5min epoxy and two clamps, so no big deal. I can imagine when you begin pushing on the front of the controller to seat the new buttons, this may happen to you. If so, write back if you need further help. PM if you desire and I will gladly be of assistance.

Secondly, pullng on the plastic switch stem hard enough to remove the buttons may actually damage the little switch stem. If this happens, the switch will extend to far, preventing the pawl from locking in the next switch. Remote possibility, but mine is just that way. The "O" or off button does just that (had been damaged before and I have lived with it...long story), and has to be held in slightly to allow one of the other buttons to engage. I have decide to replace my controller for this and other reasons, so I am not worried by this. If your controller is functioning properly, you may want to just clean up the buttons, like strife posted above, without removing them, and be done. Just realize, if you do mess up, a replacement may be necessary at $200US plus...

Good luck...

[SLeazy Rider]

Thanks for the excellent advice everyone. I'm not sure right now if I'll try it myself or just let my indie do it for me the next time I take the car in for work. I would hate to damage the entire unit and have to replace it. And the buttons DO need to be replaced rather than just cleaned. The "automatic" button on the right is completely missing; the decal for the the "off" button is missing some black in the middle of the "O" (looks like it's either been over-used or someone pushed it with paint thinner or fingernail poslish on their finger); and the decal for the "compressor" button is gone.

Glenn

[Walrus]

Originally Posted by SLeazy Rider

and the decal for the "compressor" button is gone.

Glenn

Are you referring to a button labelled "compressor"? My 1988 has, starting at left, a defrost symbol: MB Designation "A"
then two solid arrows, one point up and one down: MB Designation "B"
then a solid arrow down with a outline arrow point up: MB Designation "C"
then the same with econ printed over the arrows: MB Designation "D"
then a "O"... MB Designation "E"

The compressor is energized with each button except off (E) and arrows with "econ" printed on it(D).

[derryb]

or you will get them mixed up like i did. Easy to break old button popping it off, but hard to break new one putting it on.

[SLeazy Rider]

RM, the one with the missing decal is what you call "MB designation C." I have the appropriate replacement (the whole button, not the decal).

Derryb, thanks for the additional advice.