I have a 1995 C220. My symptom is no sound when I press on the horn. I'll check fuse 5 now, but I remember fuse 5 is designated to protect the left low beam and it says nothing about the horn so I assume they are not in conjunction. Yup....just checked....and for what its worth fuse 5 is good.

Greg

'95 C220
Midnight Blue
Carlsson Aero Kit
Lorensor Exhaust
Alpine IVA-D310