After searching hi and lo for a decent wiring diagram for my 1985 F350 dually diesel crew cab 6.9 diesel to repair the ENTIRE underdash to engine harness, I finally found
Auto Books Bishko Sales
[email protected]
(800) 544-3312
They have copies of the ORIGINAL wiring diagrams from Ford.
You will get about five LARGE pages of wiring diagrams for all areas of the truck.
Nothing else I obtained was as good.
You MUST buy these and TREASURE and PROTECT them from loss.
They are impossible to find anywhere else.
Mine copies had a rust mark where the staple had been because they had some moisture get to them while they were in storage. Also, some minor holes in the paper.
That's what you get. So take it.
I asked them for a fresh copy and they offered a refund if I didn't like it.
I kept my copies.
This is the best you will ever find as I don't think you will ever find the original Ford book from which they were copied.
I paid $100 for the original Factory manuals and they didn't have ANY wiring diagrams in them.
These copies will cost you about $25 dollars or so.
Buy them and solve your problem.
By they was, these year Ford trucks ALL have shorted wires under the dash.
I have been in junk yards trying to find a good harness and most of them have a burned fuse box.
Mine shorted under the dash on the driver's side where two wires melted together. I"ve been patching things together for over five years now.
Note: SOLDER YOUR CONNECTIONS...CRIMPED CONNECTIONS CAUSE HEAT AND RESISTANCE.
If you remove your dash to get to all of the wiring in the harness. take pictures or you will have a nightmare on your hands putting it back together.
It's the worst designed arrangement I have ever seen. Rusted screws holding frames together where you can't get a screw driver on it.
You will become crippled laying on your back trying to see under the dash.
Good luck