Cruise control
 

Howdy. New to the forum. Cruise control is non-functional on the 1978 300CD I just purchased. Most common causes and DIY fixes would be appreciated.

Thanks in advance.

Bud

Generally the cruise control amplifier/brain that is mounted under the drivers side kick panel. This is assuming that the cable is hooked up from the vacuum servo and the servo is good. Signs of the amp being bad is the cruise will engage when the lever is moved but won't hold when let go.

Cruise problem
 

I also have a cruise problem. Mine is an intermitant problem. Cruise seems to work at 70+ mph intermitantly. Cruise rarely works at slower speeds. This leads me to believe it may be related to a vacuum problem. Higher rpms generate more vacuum. Any thoughts???

Ed

Ed, what year and model is your car?

1992 300e.