I've got a 1993 300TD and it didn't start today in the cold. The glow plug light didn't even turn on. Came back this evening after work and popped the hood and first looked at the fuses and looked no further as a red wire running along the inside edge of the fuses (within the box) was cooked. Obliterated. It burned up most of the paper fuse diagram that sits under the box cover as well. Some fuses below this wire are black but otherwise look OK. I'm guessing this wire is my issue with the glow plugs...although all other electrical components of the car work even with this fried wire.

The red wire is severed in two from the burn...but it looks like it was connected to itself by some sort of fuse as well. Whatever fuse was there is gone/melted but there is a rubber boot, that didn't fully burn, which likely held this fuse.

So I'm wondering:
1) what was there exactly at that red wire connection?
2) is there a source for a fuse diagram so I can see if the correct fuses are being used?
3) is that red wire a connection for the glow plugs...and if so would a faulty glow plug cause such a reaction?

Thanks guys!