Cruise control switch bad?
 

When first setting cruise on '89 560SEL, car accelerates until lever is pushed down, then speed settles where it was set. Also, after if I turn cruise off, it will not turn on again until engine is switched off and restarted. The resume function does seem to work after braking. Is this likely to be the switch, or some other part of the system. If it's the switch I'd like to change it when I replace the ignition switch which I know is failing. Thanks

I have '84 300SD with EXACT same symptoms. I phoned Peter? (at GDL) and he indicated CC ECU was the culprit and said to send it infor refurb. I may try the circuit board check and resolder route first. If anyone has had a "cure" for the "restart to reset" problem I'd be interested as well. Thanks.

Bruce