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.