[stingroyer]

I have a 1993 190 E, 2.6 with 111,000 mi. Most of the time the speed control only holds in for 2 - 10 seconds. It will hold speed, surge a little and then drop out. However, on occassion, I've driven >100 miles, using the cancel and resume function. Any ideas on where the problem is?

 

[MTI]

Intermittent control could be one or more of several faults. First, a stretched or faulty speedometer cable will cause a "bounce" in the needle that will prevent the cruise control from latching. The cruise control amplifer might have an bad/cracked solder joint that is barely making contact, which is a common fault at this age of the circuit board. It might also be a sign that the cruise control actuator, on the throttle, might need replacement.

 

[edfreeman]

I have the same (or, at least, very similar) issue with my 1993 190e-2.6. The speed control surges and the speedometer will "flutter." Sometimes, it will go for hours without an issue, sometimes, I won't be able to use the cruise at all on my weekend 400 mile trips. The service guy I regularly use wants to put in a new speedometer, but I'm skeptical that it's the problem (doesn't make sense to me that the cruise is fed from the speedometer, though I could be wrong). Anyone out there solved this problem?