Gm parts help!

[CamaroZGuy]

so my shop has run in to a major problem and i need some collective help from GM brains.

for the past month or so we have been fighting electrical problems with a 2004 Chevy Suburban (Up Armored) with an 8.1L. after countless hours of chasing wires we found the problem....1 wire going in the back of the fuse block under the hood.

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this is what we are needing, we can get the part number for the connector its self, but the harness that is labled #5 cant be found. the main problem is we have to sorce all are parts either through the Air Force supply system or a 3rd party company. we are being told that GM no longer supply's the harness needed.

if possible need help trying to find the harness OR if some one can point me to a sorce to get the required parts to re-pin the harness