Just purchased a 1984 300CD w/150k for my daily 200 mile work commute. The cruise works but is so annoying, I don't use it. It accelerates over the set speed, then adjusts itself by slowing down below the set speed, then does it all over again (5-10 second cycles). The ball and socket connectors on almost all of the throttle linkeages are loose/worn. Is this a likely cause or is the control unit the most likely culprit?

Both can cause this, Just remove the ball connections one at a time and clean them and squirt some grease into each one. That's all there is to it!
If this does not help, the control unit is the next stop.

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Benzmac:
ASE CERTIFIED MASTER AUTO TECHNICIAN
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