It seems to be a yellow and black wire that fried from starter relay back to fuse panel. Connected just to left of fuse panel. Need help identifying what this wire does and how to fix
What year and model (standard, XR7)?
Most likely it is the main power feed to the interior of the car. This wire feeds the ignition switch, accessories, lights, etc. If it’s melted you have/had a bad short somewhere and need to find and repair it before replacing the burned wire.
1968 standard
I traced it back to fuse panel mounting bracket. It was plugged in next to another green wire. I pulled it off of where it was plugged in and car started and I was able to drive it to shop.
Yup, on a 68 that is the main power feed. Inside the car it splits to feed the fuse block, ignition switch and headlight switch.
Ok thank you
Looking for some education. If the wire feeds the ignition switch, how could the car be started with it disconnected? I fear electrical problems. 
Power lines are black/yellow, not yellow/black, and are either 12 or 14 AWG. There are two uses for true black/yellow wires (all 18 gauge): the radio power feed, sometimes tied into a PRNDL female bullet just below the fuse box, and an alternator indicator lamp that goes to the instrument panel connector.
Yeah sorry black wire with a yellow tracer. What I could make out it was severely melted. Looked to be a 12 gauge wire. It was tied in with another wire at starter solenoid. Then it ran by itself all the way back to fuse panel bracket and has a rubber 90 on it plugged in next to another green wire with a 90. I was riding the brakes alot coming off a hill when it happened. Not sure if this is some sort of a brake switch or turn signal switch.