Calling All Wiring Gurus

[bcoke]

72 Blazer with all sorts of electrical issues. Trying to trace wires and get rid of all non-essential aftermarket stuff to simplify, while keeping / organizing / labeling as much of the necessary wiring I can.

Okay so this one's a doozy - weird situation, and I could use your help figuring out what's going on (pictures attached to help with clarity).

I have a Kenwood KDC-125U head unit in the dash. The wiring diagram (attached) says that the yellow wire coming out of the head unit connector is the battery wire. On the current setup, that yellow wire is connected to an orange wire (attached).

When I traced that orange wire, it first connects to my headlight switch (attached)...I have no idea why. It seems like it attached on the accessory pin, but I might be wrong about that.

And as you can see, something is wrong with the headlight switch setup because it's melted (attached) - maybe because of this?? Fingers crossed this solves it.

At the headlight switch, it's connected to another orange wire that goes to the back of the fuse box (attached). I tried to take it off, but for the life of me I couldn't get it loose. It seems like that attach point corresponds to the middle "TAIL STOP" fuse on the front (attached), but I think that's for the tail light....so I have no idea why it's connecting there.

At the back of the fuse box it links up with ANOTHER orange wire that runs to a connector with two orange wires (attached). One of those wires goes to what seems to be a housing for an under-dash light? (attached). That's at least what it seems like it could be and it was attached with a screw under the front of the dash. The other orange wire goes to a connector that hooks up to the base of the steering column along with some other connectors (attached).

Okay so does anyone know why a battery wire from the radio would be going to a headlight switch, the fuse box, an under dash light, and the steering column? Can I remove the orange wire if I'm removing the radio / speakers or does it play a critical role? The connection to the steering column has me particularly wary.