Wire identification help

[84_c10_GMC]

Good morning, got my new American auto wire harness for my 84 c10. Checked pins on new harness vs old harness where connects to fuse block and matches up. But I have a few wires in new harness I’m not sure what to do with. I believe I know where one is suppose to go but someone changed oem stuff on the truck. Someone “wire tucked” the original harness is the reason for the new harness.

First picture will be the new harness wires and 2nd picture is where I believe the one with a single eyelet goes. But I am not sure what the long rolled up pink wire goes to. Or the black with the 2 hole bladed connection. There is one wire I’ve found off old harness that goes into a wire loom along frame towards the back. But it’s larger than the pink wire. About to crawl under and try and run down where it goes to.

 

[EvilGenius]

I believe that pink one is the fuel tank level sensor wire. It snaps onto a port on the sending unit on top of the tank.

 

[84_c10_GMC]

I believe that pink one is the fuel tank level sensor wire. It snaps onto a port on the sending unit on top of the tank.

Ok that makes sense now! Thank you

I need to drop the tank anyway and dump all the old fuel out.

 

[EvilGenius]

That black one looks like it goes on the factory junction block that you no longer have. The second Pic you have is where it would be. You can probably just hook it up on that replacement junction block in your Pic. You can see in your Pic the wire on the left most connection is the same as your new one with 2 red wires merging into the black one.

 

[84_c10_GMC]

That black one looks like it goes on the factory junction block that you no longer have. The second Pic you have is where it would be. You can probably just hook it up on that replacement junction block in your Pic. You can see in your Pic the wire on the left most connection is the same as your new one with 2 red wires merging into the black one.

So would both wires most likely go on the block? All the wires going to the black wire are red. Then combined to a single wire that’s black.

 

[EvilGenius]

So would both wires most likely go on the block? All the wires going to the black wire are red. Then combined to a single wire that’s black.

That black wire is most likely a fusible link to protect the trucks main circuits. The main bulkhead connector has 2 main power wires that feed the cab. I think circuits 2 and 3 in the service manual. So those 2 circuits are what connect into that black wire I'm thinking.

That junction block should be a battery positive block. So another connection that should be on it is a fat wire that goes directly to the battery, or to the positive lug on the starter.

 

[EvilGenius]

The factory 12 v path is battery, then starter, then junction block, then those 2 power wires into the cab.

Anything in the engine bay that needs power is fed by those two wires and is fused inside the cab on the fuse panel before heading back out into the engine bay through the firewall connector as a distinct circuit. This is why the headlight relay mod is popular, that's a lot of connections and light gauge wire before power gets to the headlights.

 

[84_c10_GMC]

That black wire is most likely a fusible link to protect the trucks main circuits. The main bulkhead connector has 2 main power wires that feed the cab. I think circuits 2 and 3 in the service manual. So those 2 circuits are what connect into that black wire I'm thinking.

That junction block should be a battery positive block. So another connection that should be on it is a fat wire that goes directly to the battery, or to the positive lug on the starter.

The one eyelet goes to the starter wiring. Appreciate the help. All my c10 experience was 67-79 models and didn’t have any of this lol