It is a red 14g wire that come out the back of the under hood fuse block.
It is on one of the lugs that the positive battery cable is bolted to inside the fuse block.
It runs back into what appears to part of the stock harness and then runs down the firewall and under the LJ on the driver side.
I have not crawled under to trace it yet, but was hopping someone would save me the trouble
Thanks! 2004 LJ