Howdy folks!
My son bought this flareside 82’ F150 Ranger with 351w and C4 tranny at the end of August. Had number of fly wheel/starter Probs, oil leaks ect…
So we pulled motor, new gaskets, starter, flywheel, 1403 edelbrock, new fuel sender, new manual fuel pump, got engine compartment and frame treated and painted. New gaskets and motor paint along with a pertronix Flamethrower II coil, distributor, and power relay. Put the motor back in, hooked everything up. Was turning over but not sure if i was getting fire. While checking out battery, grounds and connections, my son said, shouldnt we ground this and handed me a black wire that i proceded to connect to ground in front of battery and saw a small spark and lost all power to dash and in cab. Motor wouldn’t turn over (disconnected black wire BTW), unless my son would hold this wire just right but still no power to cab. Very janky wiring. This black wire splits into a red wire going to back terminal of starter relay, a smaller red wire that goes to connection with green wire and two yellow wires (one bigger than the other) then splits to a yellow wire that goes to what I believe is a voltage regulator. FYI, hooked my pertronix relay to the brown wire from the cab that the last Dick Dufus and ran to an HEI unit that i took out. Motor not acting like it is getting spark.
any takers?? Thanks in advance!
Does anybody know where this mysterious black wire with an eye connection go?

 

Your mysterious black wire was more than likely the alternator charge wire. If you look closely at the wire, if it has a faint orange stripe, that is what it is. When you grounded this wire, you blew the fusible link. It is a colored rubber thing in the wire right where it bolts to the large terminal on the starter relay. It sends power to everything in the truck except the starter itself.

 

Wiring diagrams are here:

https://www.garysgaragemahal.com/1981-evtm.html

Those are 1981 but your truck should be similar. See pages 12-15.

Hopefully damage was limited to a blown fusible link. Take a look through those diagrams and see if you can identify the mystery wire. As Dave mentioned, sometimes wire colors fade over the years, especially printed markings.

If you need more help, please let us know if the dash has an ammeter or battery warning lights.

 

Welcome to FTE

I had something I started last night but being I had to get up at midnight for work I for got to finish it and hit send
What I was going to say is what Dave & Karl posted.

Good luck and let us know if you got it fixed or need more help.
Dave ----

 

A C4 in a full size truck? Not only that but behind a 351W?

Sounds like a fuse or fuseable link blew.