Gentlemen, I have an '86 300E with a faultiy cruise control. When I put the cruise on it engages, disengages, engages, disengages in a rapid fashion and keeps this jerking up unless I am going uphill in which case it seems to be fine. However as soon as I get to level ground or downhill the problem starts again. Would my problem be the amplifier or the actuator or something else? Thanks for your advice.

Alex

Alex,
Had the same cc problem with my '86 300E. Since I fixed it (about a year ago) it has worked flawlessly, so I must have done something right!
Actually there are 3 things worth doing:
1) remove the amplifier and carefully resolder all joints on the circuit board, as well as the connections to-and-from the board.
2) clean and oil (or light grease) the throttle linkage and joints.
3) clean and tighten the relevant ground connections in the cruise control circuit.

I did all 3 jobs at once, so I'm not sure what each of them contributed to solving the problem. The first, is probably essential; and the last two should be done anyway. You could always try the last-two first (they're the easiest), and if that doesn't work then pull the board.
Good luck, keep us posted.

Barrie

INSTALL A 33 OHM 1/4 WATT RESISTOR IN SERIES IN THE BLUE WIRE TO THE ACTUATOR,THIS IS BEST DONE AT THE CONNECTOR

M.F.

Thank you for your advice, I will try and see which one works better. Thanks again.

Alex