Go to w124-zone.com, register for their site, and go to the online service manual.

Under chapter 24 there is a complete set of schematics for the car.

I don't have handy the manual for the 91-95 124s but on the 1st gen 124s the marker lights are on fuses 3 and 8.

Also check your big light monitor relay in the back half of the fuse box. It is the huge relay on the outboard row and just about every light circuit in the car goes through there. I recommend undoing the inner frame of the relay box and lifting out the relay with the wires still attached, it is a pain to plug it in from the top.

__________________
The OM 642/722.9 powered family
Still going strong
2014 ML350 Bluetec (wife's DD)
2013 E350 Bluetec (my DD)

both my kids cars went to junkyard in 2023
2008 ML320 CDI (Older son’s DD) fatal transmission failure, water soaked/fried rear SAM, numerous other issues, just too far gone to save (165k miles)
2008 E320 Bluetec (Younger son's DD) injector failed open and diluted oil with diesel, spun main bearings (240k miles)

1998 E300DT sold to TimFreeh
1987 300TD sold to vstech