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.

__________________
Current stable:
1995 E320 149K (Nancy)
1983 500SL 120K (SLoL)

Black Sheep:
1985 524TD 167K (TotalDumpster™)

Gone but not forgotten:
1986 300SDL (RIP)
1991 350SD
1991 560SEL
1990 560SEL
1986 500SEL Euro (Rusted to nothing at 47K!)