Cruise Control. One of my favorites.

Yes... do search the forum. There are several options:

1.) if you are good with a soldering iron, you can retouch all the connections with a 35 watt solder iron (pencil type) and that will fix it about 75-80% of the time. Based on your described behavior, your CC is a prime candidate for this technique.

2.) Get an after market rebuild at about $270. Advantage here is there may be a warranty.

3.) If you are looking for true MB OEM, it is about $600 from the dealer as they want to sell you the brain and the Control Chip.

Location of Cruise Module:

once you remove the knee pad under the steering wheel, you will see a silver box 6 inches long, 4 inches wide and about a 1 inch thick held in by two 8 mm bolts. That is the CC brain.

Good Luck