I have a '86 K5 with the 5.0L and two separate times when I turned the key to start it just clicked. I thought maybe the starter was going, but the third time when I turned the key to ON or START there was no power at all. No dash power, no headlights, or horn. I knew it had to be more than a starter. I used my multi-meter and worked my way from the battery and saw I had power all the way up to the harness that plugs into the block junction at the firewall right under the master cylinder. I unbolted/unplugged the harness and found all the terminals melted.

Not sure why it happened but I can only think it was from when the battery was not secured to the rusted tray and fell off a few times when off road.

I'm not too sure at this point how I should go about repairing this. Should I go to a junk yard and try and cut and splice new connectors? I work at a Chevy dealership and had our parts guy look it up for ****s and giggles and its discontinued. Help?

 

Wow that's not good. I'd try to find a whole wiring harness both inside and out. At the very least, you'll have to get both ends and splice all of the wires over.

 

Do you think it's possible to find that exact harness from a junk yard? Not sure if anyone on here has access to something like that

 

UPDATE: That harness is NOT melted! lol After going to a junk yard and unplugging the same harness on another truck, they are all like that. It is some type of grease GM put there from the factory to preserve the connections.

After getting home and looking at my battery I realized that the body ground wire as completely severed. I ran a nice new thick cable to ground the body and sure enough the thing fired right up. Go figure

 

Well that's good news indeed! It was difficult to tell from your picture and sort of looked like there were some missing contacts in there which followed with your original description of the connector. Glad you got it figured out!