Climate lever jam

[adamzeller]

Hi friends! Can you help me? The lower left dial is jammed and I don’t want to break it! How can I fix it? It’s a 1967 Mercedes 250SL

[Jonny B]

Hard to see much awry from the photo. Is the lever further out of the slot versus the others? Did it happen all of a sudden, that is no indication of being stuck or hard to move before the jam up?

It could be jammed in several different places. Heater box flap, connections within the control unit? Have you tried taking out the glove box to see if there is any visible or loose.

Excuse my misread of the original post - that lever controls the heater valve. Take a look at the heater valve which is visible if you take out the round rubber cover at the top of the firewall in the engine bay. See if you can see anything loose or trying to move when you push gently on the leverl.

To replace the lever is a real pain, but not impossible.

[badali]

I think that lever controls the valve and flap seen through the rubber plug in the fire wall.  Check to see if there is something stuck or broken in there.  To do any repair you may have to remove the air intake vent.

[rwmastel]

Brad and others,

I can't recall - are the cables and linkages visible if you pull out the air filter from the cowl air intake area?  That's an easy DIY job (and a good opportunity to replace that filter).

[badali]

I replaced the flap in mine through there and the intake filter.  Mine had a mouse nest in it at PUB many years ago and water came into the car since the drain was plugged.

[kampala]

The Lower Left controls the Heater VALVE as mentioned.   When it sticks (if not sudden) it is most likely the o-ring at the valve.  Access, as advised by others, through the rubber plug at the firewall.  Not difficult to do, but detail instructions really really help to avoid issues.   This is detailed very well in the tech-manual.

If you decide to join as a full member the tech manual will be available to you.


You will find it in the tech manual under Heater.   There's a great write up with photos.

[DavidAPease]

I will just add that the climate control lever does not operate the heater valve directly, but operates the heater air flap; that flap then also pushes or pulls the heater core valve arm.  So to see everything, it's necessary (as others have said) to remove both the rubber valve plug on the firewall and the air intake scoop and filter.  (And as Rodd says, clean or replace the filter while you're at it.)

            -David

[Pawel66]

And make sure the drains are not clogged.

[rwmastel]

Now we just need Adam to come back and find all this wisdom posted about his question.  He just joined yesterday so he could post this question, so maybe he doesn't realize how active we all are!