I think it is about time to get rid of my original cruise control. If you type cruise control repair in Google, you'll see a lot of web pages discussing MB cruise control repair. All of you probably have experienced problems with your cruise control. That just proves how junky the MB cruise controls are.

Here's my plan. On my 1984 300SD, I plan to take out the electric actuator and amplifier and replace it with a vacuum actuator type system. I don't think anyone has done this on their diesel, so I will be first when the parts at junkyard go on half price soon. I want to use a GM type cruise control because I can get the wiring diagrams for it real easily.

One of the things I need to know is whether the car has a VSS (vehicle speed sensor). As I understand, typical cars have 4000 pulses per mile. Since my 300SD has an electric speedometer, I'm think it has a VSS, but I don't know many pulses per mile it does. Does anyone know?

If it doesn't, I can use magnets and a pick coil on the driveshaft. But, I probably can't use the junkyard special. I will have to buy a brand new one.

I bought a new cruise control from JC Whitney for under $100. I put it on my Dodge motorhome. It works really well. I don't see why it shouldn't work on a Mercedes with a little creativity. It took me a couple of hours to install it. I put a magnet on the driveshaft to read the speed since my motorhome is a 1971 without a VSS.

I got a unit from Autozone for $79.95 for my 83 CD.
It is made my one of the Japanese radio company's, vacuum operated, with magnets attached to the drive shaft.
It works ok, a little slow to engage but holds the speed well.
I left all of the old parts in place and just added the new unit, the only thing I don't like is the push button control, you can't use the Mercedes stalk.
Jerryb

Great to hear jerryb could make an after market cruise control work on a diesel. I'm sure a lot of diesel MB owners will find that good news. I'll visit Autozone to see this cruise control.

Just wanted to let you guys know that my cruise control is fixed. I stumbled across a lone 1985 380 SE at the junkyard today. I pulled the actuator and cruise control amplifier and plugged it into my 1984 300SD. My cruise control works just perfect now. Total cost: $10.