1985 300 SD Cruise Control Problem
 

I have a problem with Cruise Control. The original switch that should be on the steering column was in the glove compartment for months. I decided to replace it with a new one, so I ordered one and it showed up today.

When replacing it, I noticed that the original one has the following number one it... 126 545 15 24 and the new one in the box is... 126 540 05 44. They look identical. All the wires are the same colors and in the same order.

I replaced it, BUT I did a little "meatball surgery" while in the process...

I decided to undo the solder points from the wires to the switch. I wrote down the colors so as to eliminate confusion... and soldered the new switch to the old wires.

Took car for test drive and found that the cruise control does not work...

Any suggestions on what to do next? First, are the 2 part numbers OK, what I mean is, was it OK to use this new switch? They really look alike!

The Cruise Contorl Amp might be the culpert. the old switch in the glove
box might have been ok.
Did you remove it, or was it already removed when you bought the car?

Should have asked ? before doing all the solder work, or doubled checked the part# to see if it was the right one.

MB changes part# from time to time as they do improvements on the parts.

Charlie

The old switch that was laying in the glove box was actually just the handle! I stuck it back in place months ago after removing the steering wheel. I had to jam it back into place , as it has two studs that allow the handle to pivot...

when i tried the original, it seemed to accelerate the vehicle, but since the housing was damaged, the handle soon slipped out of the socket.

the soldering job was not hard at all. figured it was faster than removing a bunch of things to plug in the new wire plug...

where is the cruise control amp?

^It's located near the steering column, you'll have to remove the kick panel to gain access, it will be on a mount that has another box with it, remove both, much easier.
It's an aluminum box with a plug on one end.

How do I test the cruise control amp?

Try here,
http://www.gdl-online.com/test023.html

You might also consider an aftermarket CC setup.