Blower Switch Knob ?

[lapisblue]

Hello Everyone,

I have a 1969 280 SL and recently decided to put in new heater control discs.  I have just about everything out of the dash, radio, glove box, clock.  But I can't get the blower switch knob off.  Actually, I appear to have broken the plastic knob itself off trying to pry it off the stem, but a nut remains on the stem, and behind that a chrome nut that wants to screw off, but will only go so far.  Can anyone tell me how this knob is suppose to come off??

Thanks much.....Jack

[ja17]

Hello Jack,
Unscrew chrome bezel and the knob will come with it.

Joe Alexander
Blacklick, Ohio

[waltklatt]

The small aluminum nut that came off can be reinserted back into the plastic knob easily.  Be sure to line up the ridges correctly and press it back in.  The chrome nut that holds the switch to the dash can be uncrewed easily.
Walter Klatt
1967 220SL-diesel
1963 230SL-gas

[tdun824259]

It's my understanding that the blower rheostat knob is lighted.  Is that correct?  And if so, I'm still not understanding the method of removing the knob itself.  Do you just pull!  My blower rheostat knob will not light and doesn't seem to respond to pulling on it.  I'd rather not break the thing.

thanks
Tim Dunagan
1971 280 SL

[114015]

Hello Jack and Tim,

Yes, you can just unscrew the chrome nut (bezel) that holds the knob to the dash as Walter described. Then the knob comes with off. It is attached to the nut. When you had it pryed off I do not absolutely know how to pry it back. Please see Walter's descriptions below.
As to the light in the blower knob, this was illuminated only in the early style knob; i.e. until 250 SL serial no. 002979 but not thereafter.

Best,



Achim
(Magdeburg, Germany)

[jeffc280sl]

The knob itself has a spring loaded clip on its base which mates with a shallow groove in the chrome bezel/nut.  The clip groove setup holds the knob in place.  The knob can be removed by pulling it out from the dash which releases the clip.  A spray of WD-40 may help it release.

Jeff C.
1970 280SL 4-speed

[tdun824259]

Achim and Jeff,

Thanks so much for your help.  I should be able to win that battle now with that stubborn knob.  I'm disappointed about the non-illumination of the knob in the 280 SL's.  With all the US spec's I would think that would be a nice safety feature in having the knob illuminated rather fumbling around in the dark trying to adjust the fan speed.

Tim Dunagan
1971 280 SL

[114015]

Hello Tim,

Yes you are right but these old cars don't have the favourable illumination of the dash for every little switch like in modern cars. Basically, there is only very little illumination besides the instruments (-cluster) which is the background light for the heater discs. The little light in the ventilation knob only lights up when you turn the blower on and shall remind you to turn it off again in time.

Well, we have to live with that but therefore the colored illumination of the heater discs is just stunningly beautiful.

Best,



Achim
(Magdeburg, Germany)

[lapisblue]

Re: removal of the blower knob, thanks for your replies...a little WD40 and a pair of vice-grips finally did the job...I pretty much sacraficed the aluminum nut, however I needed to know that this was what was required before using brute force...new knobs apparently are available from a dealer for $21, although I'm sure I can get my mechanic to find me one....now I get to play with the heater discs *#& thanks again

[Jonny B]

Good luck with the discs. There are a large number of posts on the site regarding how to do this, tricks and tips, so be sure to check them out via the search function.

Jonny B
1967 250SL Auto