You can find a fuse box diagram for a 1985 Ford E350 7.5 liter inside the owner's manual. You can also find it in the vehicle's Chilton repair manual.
http://wiki.answers.com/Q/Where_can_you_find_the_wiring_diagram_for_a_1982_ford_e3501982 ford e350
My 1991 E350 Fuse diagram is in the owners manual.
your local ford dealership
A diagram for a 1994 Ford e350 can be found in the trucks service manual. The manual can be found through most auto parts.
diagram to replace belt on E350 1994 7.3L
goto: www.installdoctor.com on internet
Check the related link, I found a picture of the diagram posted on the inside of the engine compartment. Your next best bet would be a Haynes or Chiltons manual.
1985 ford f150 5.8 h.o.vacuum system diagram
fuel strainer location on e350 van
You can find a 1985 Ford F 600 wiring diagram in most Ford service manuals. The service manuals can be found at your local library.