this has been a very insightful thread as my CC in 300sd does not work. i am wondering how to determine which parts need replacing. the amp or the actuator.
when i hold the level up for about 10 seconds i feel the cruise control grab as but does not lock.
last night i drove 250 miles (see shakedown thread)
with no cruise. this is on my imediate list of things to fix. after reading this string i am still uncertain....my gut is to just replace all the parts save the lever switch. i have not the patience to send parts back and forth...