Exactly right. Fuse #6, 8Amp, white (in the fuse box under the hood on the drivers side) controls all 3 of those functions on my '87. Probably just a fuse vibrating itself to pieces over time, but if it happens again, another underlying problem, such as a short, may be causing the problem. Example: I kept blowing the fuse for my passenger taillight - it was a short in the cigar lighter! Hope it is just a fuse.
2003 Firemist Red/grey leather SL 500
2015 Palladium Silver/black mbtex GLK 350
1987 Smoke Silver/burgundy mbtex 300E Sportline (SOLD)
Click to see 87 300E