Originally Posted by Diseasel300

The solenoid block is a *VERY* common source of problems on W124 and gen II W126 cars. The printed circuit board inside is a cheap design and the solenoids routinely break free and cause all sorts of intermittent issues. It's repairable, but you have to take a knife or saw and cut the case apart.

Given that you're having multiple problems, my suspicion would be a bad ground that's common to the various functions you're having issues with. Bad grounds are common in these cars and cold weather/moisture exacerbate them.