So my sons 89' toyota 4x4 has a serious issue....His battery slid over after crossing some rough railroad tracks...causing the "positive" side of the battery to touch the metal bracket thing that holds the battery snug in its place.

Apparently, the current from the battery traveled thru the frame of the truck, and some how managed to travel up the bracket that holds the power-steering pressure hose, causing it to melt and then blew a hole in it....

I replaced the hose, but found out it has melted a ground wire (or 2, or 3) that is in the wrapped bundle of wires that goes thru the firewall...

Does the wiring harness need to be replaced?

Is there anythig online that shows the wiring-harness?...I'm not sure i am smart enough to replace a wiring-harness with-out a guide of some sort

Any ideas?...thoughts?

Until you see how much damage is caused to the wires around the those that melted it is hard to say.

Have you looked in the FSM section at the top of the forum?