Cruise Control
 

I have a 1989 300SE. The cruise control was working fine and then ceased. I removed the amplifier and had my brother - who is in the field of electronics that deals with these components - change the resistors that on some of the videos that are on line suggest to change. Did not solve problem. I bought a rebuilt actuator and installed that. Still no functioning. Several questions: Can I do a test on the amplifier to see if that is functioning properly? Could the amplifier code unit failed? Should I buy a new amplifier and forget about the new resistors in this current unit and chalk it up to "nice try"? I have seen on-line issues that can arise from the yolk in the steering wheel, but all points primarily to the amplifier, so... Any suggestions would be helpful to steer me in a better direction.

every bloody time i messed with that generation cruise setup, it was always the amp. we had the oe tool for testing, which replaced the amp and then you push the buttons for whatever function. never, ever had any other part fail. good luck, chuck.

Go and check the wiring at the connections. You have to open up the plastic covers on the end of the plug and see that the wires are still attached to the pins. Real easy fix, just resolder the wire back into the connector.

Replaced the amplifier and all is working just fine. So, textbook suggested fix.