If I read correctly you have 3 sets of wires on the output side of the fuse block.

Remove all 3, adding back one at a time and using the fuse box cover data to see what might be working. The one added that blows your fuse is sure the bad one giving you a way to go further.

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1985 300D 198K sold
1982 300D 202K
1989 300E 125K
1992 940T

"If you dont have time to do it safely, you dont have time to do it"

"The democracy will cease to exist when you take away from those who are willing to work and give to those who would not."

Once you know what is on the fuse, disconnect all of the loads. Alternatively, connect an ammeter across the (empty) fuse terminals to measure draw. Then disconnect items on the circuit. You'll learn more than you ever wanted about your wiring. Most problems will be at a switch, junction block or load. Most wires are good.

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85SD 240K & stopped counting painted, putting bac together. 84SD 180,000. sold to a neighbor and member here but I forget his handle. The 84 is much improved from when I had it. 85TD beginning to repair to DD status. Lots of stuff to do.

you are right. The radio is in fuse 2. I used 1 of the 3 covered poles (C105) found in the front pasenger side fender to supply a constant 12 volts to my amp. I think i used the middle one. Had to replace the bolt with a longer one though.

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'85 300D Cal 280,000 miles
'14 GLK 350 60000 miles

This link works for the wiring diagram. It seems to have all the bases covered, including the visors and the rear pax light. http://mercedes.thatchermathias.com/w123CD2/Program/ETM/83_300.pdf

I used the paper version of the FSM and show fuse 2 feeding 7 wires from the fusebox. This is for the '81 300D, since that's the latest version I've got:

The antenna does get power thru fuse 2.

For possibilities for the short, I'd consider:

1) cracked joint/connector in the instrument cluster (clock)
(if the diagram's correct, you may be able to isolate at the trunk connector)

2) bad door switch - should be able to unscrew and inspect for rust/corrosion

3) problem in the console with a pinched wire or a botched PO radio install or removal - you can also check the flashers