What does this thing do?
 

In adjusting my tranny linkage today, I noticed a new thingy and was wondering what it is/does?

On my SDL, if you were looking at the fuse box, immediately above it, between the fuse box and the firewall,, there is a little dial/knob with numbers on it.

What is it?

What year please.
 

???? 300 SDL - 330,000

What year please.

It's the idle adjustment......
 

#4 is considered the normal idle speed at 630 rpm's. To adjust it you pull up on the knob,THEN turn it. #1=570, #2=590, #3=610, #4=630, #5=650, #6=670, and #7=700 rpm's. ( At least for 1987.) Just compare it with the tach.

Sorry, it's an 87SDL..

Thanks for the response. I'll check to see what it's set at.

Idle speed control/altitude adjustment. Idle speed (other than base) is electronically controlled on the 603.

Peter

PSFRED,

So unless I am driving at altitude, there is no reason to ever touch that thing? Should it be at 4 or would it make a difference at Sea level?

Thanks

At what rpm is a 1987 603 supposed to idle at sea level? Thanks I was wondering what that knob was for.

The CD manual gives the idle spec as 630 +/- 20 with the idle speed controller attached, 570 +/- 40 with the idle speed controller detached. Knob at position 4 in both cases.

FWIW, the Klima relay disengages the AC compressor below 600rpm but I don't know how accurate that device is.

Sixto
95 S420
87 300SDL