FoxGT

That's the engine relay.
If the fusable link inside it went I'd say it was probably because the wire touched to a ground somewhere, but while it may have blew there's a chance a small connection could still be made which may be what is draining your battery. The fusable link connections are practically right off the solenoid though.

I'm not sure where the orange wire is going, I can't tell if it's the switching wire, constant 12v, ground, or power to the sensors. Any chance you can get a picture of the back of the relay so I can see where the wires enter the back of the relay? If that is the 12v source coming directly from the solenoid then either the wire got pinched somewhere or the insulation may have dry rotted & is touching something or maybe the link just popped...

I don't really have any wiring diagrams to go off of because fortunately from all of my friends mustangs i've had to wire I have noticed not one of them was colored correctly to match any of the wiring diagrams i've seen.

Not saying i'm 100% sure that's the problem but since it isn't working right it's a good possibility.