HELP!

I have a 2001 Silverado Z-71. Several years ago my headlights started flickering and I found the trouble in a broken wire on the Multi Function Switch wiring harness where it plugs to the MFS. I repaired the broken wire and it's worked great until last week. The headlights went out again so again I looked at the MFS and found that the wire I repaired plus one more next to it were burned, slightly melting the wiring harness connector. Splicing new wires didn't work so I bought and installed a new MFS which came with a new wiring harness. Still no headlights and now I have no interior lights, no under hood light, no cargo light, the key remote wont work the door locks AND the truck wont start!

I have an MT2500 scan tool (Snapon brand) that will communicate with all vehicle functions except the Body Control Module. I think that I may need to reprogram the BCM or buy a new one. I retreived one DTS code, P1626 Vehicle Theft Deterent, so the truck is in lock down (turning off the injectors).

Has anyone had this problem? My Chevy dealer is stumped (which is usual for them) and I don't want to tow my truck to them so they can keep it for a month a charge me $2000.