W126 rear demister not working
 

Hi all, as per the subject the demister is not working at all. We have had a couple of days recently where I drove the car for a prolonged period with the rear window heavily fogged and the demister didn't work. The dash light comes on and the fuse checks out okay but still no demister. Anyone have any thoughts?

Matt.

Check power at the window
 

Greetings Matt,

Have you checked for voltage at the window plug itself? If you have power there, I'd suspect a break in the window wiring.

Charles

Thanks can-do, where abouts is the plug for the rear window? I just had a look and could not see it.

Matt.

Take a look by the window pillars
 

Greetings,

If your Euro model is like the U.S. spec vehicles the connection is under the rear window pillar, in some cases there is a connection on each side, on others it's a single connection. Look to see where the electric window strip widens slightly a little lower than where the seat belt harness attaches to the side frame. Your connection is under the molding at that point.

Charles

Is your rear window delaminating (white, milky appearance around the edges)? This can play havoc with the defroster if it is serious enough.

I have an 89 300SE and have been noticing my rear window getting a bit "milky" around one edge and sure enough, the defroster isn't working in that area.

It looks kinda cheap when your driving such a nice car the the rear window has this three inch line of frost going across it...and of course right across the area I need to see!

Is this an expensive replacement?

Mattman: I replaced the rear defrost switch in my 82 300SD and it worked great. I bought the part from:
www.************************

They specifically cater to Mercedes and they've got things you've never seen before. Super customer service too! (No, I don't work for them:p )

I JUST called my local MB dealership to find out what it would cost to replace the rear window...get this...$910

Thanks Kelly and Charles, luckily my window is not delaminating so I won't be faced with that expensive repair. I appear to have two strips that run on either side of the rear window behind the molding that also hides the rear seatbelt. How difficult is this to remove to get access to the plug to check for voltage?

Cheers
Matt.

It pains me to think that in New Zealand you call it a demister. In Canada we call it a de-froster in the summer and a de-icer in the winter <G>.

I sure envy you.

Reno

...let's just call it the "heated rear glass" :D

I may just leave mine the way it is. I really want a Garnet 560SEC anyways.

renok....why does it "pain" you

Hi Bzoo,

Right now the temperature is 30 F in Montréal. In a month's time we'll be flirting with 0 F. Don't take me wrong, being an avid skier I love winter. But 6 months of it is a tad much.

Reno

Hi Renok..was in your fine city about 3 weeks ago..Being from Florida for the last 30 years I can understand your sentiment fully...in the inverse.

Take care
Brian

hehe, I have only had two frost's in the last year and we are just heading into what looks like it will be a beautiful summers day. Does anyone know how to remove the rear panels to get access to this plug I need to check?

Cheers
Matt.

Chances are good that they are clipped in
 

Greetings Matt,

Chances are good that the side pillar covers are in place by way of clips on the back side pushed into holes in the pillar frame.
They will most likely snap out like most other item on these fine machines.


Charles