Black wire with brown stripe and orange dots, 14ga.
It is inside the harness that runs across top of timing cover but has been pulled out of harness near left valve cover and cut loose. It is long enough to reach AFM or coil / igniter. ('90 3.0 pickup )

 

There is no Black-Brown, but Black-Red sometimes fades to something in that neighborhood. Black-Red is IG2, which provides 12v to both the igniter (3) and the VAF (2).

Try comparing the color of your wire to the igniter connectors. Wipe a little water on the insulation to be sure you're not reading the color of dust.

 

Yes I see the larger maybe 10ga black-red wires. I rubbed water on that smaller wire, no change, still looks brown stripe with a dot every inch or so. It's been hot too though and melted in a few places. Somebody has sure butchered things up in here.

 

I believe what you've called black-brown is really black-dirty white, and should connect from the coil to the black-white on the igniter. Does this truck run? Because, if that connection is missing, I don't think ignition is possible.

Also, the yellow/black and the blue/black should not connect together. They need to connect from the igniter to their corresponding wires in the harness.

The red/black wires, while ugly, do appear to be properly connected.

 

Yes truck will barely run but only with TPS unhooked. They had the dirty wire going to a ground bolt on fender. I took it loose but it still shows grounded. I guess the other end of this black and white wire goes to ECM?

 

No, it goes from the coil to the igniter.

 

Well I traced that melted wire back to junction block number one, fuse 5, gauge -10amp according to FSM.
What gauge is this? Nothing works on dash except battery icon thus far.

 

Here's the wiring diagram for the '93/'94. It should look similar to this. Hope this helps. Ignore the stuff inside the dotted box on the left - that's for the 22re.

 

Update: The black-brown wire is +12v to the reverse switch on the manual transmission. PO had it ran to left front fender ground point near the igniter.