cruise control issues
 

My crusie control in my 1986 190E 2.3-16v is surging back and forth. When I set it the car will stay at the speed set for maybe 2-5 minutes at best before it starts to surge. It will do small increases in speed, speeding up and slowing down say amybe 1 to 2 miles an hour, back and forth.
I need to know if anyone thinks it could be something other than the crusie brain box, the controller in the passenger floor board? I have done some checking and found that the control box solder connections will deteriorate and need to be resoldered, I have done this once and the car seemed to be better for a while and now it is doing it again. I am considering ordering a rebuilt controller, but I want to be sure it isnt the cruise actuator or something other than the controller first. There isnt much to the crusie system that can go wrong. Any opinions?

I am having more or less the same issue and although I rarely use cruise control, I'd like to know the answer......

I have the schematics, test procedure & parts list for your Cruise Control.
Email me & I will send it back to you in pdf files.
sidoog@aol.com

I have a similar problem with my 1993 MB 300E . Let me know what I should do to solve. thanks., Leo

I still dont have any answers on the cruise control issue. I am going to get the schematics and trouble shooting proceedure to see if i can narrow down the trouble. I still am unsure if the trouble could be in the actuator motor or if the culprit is the basic "bad control unit solder joints" It sure would be nice if it was the control unit, the actuator does not look easy to get to and replace