What is this wire?

[68 C10 Driver]

I installed what is a exact replacement for the OEM wiring harness. It is excellent in every respect, but there is this black wire that wasn't on the original harness. Granted, the original harness was extremely hacked up.

Here are a couple photos of the mystery wire in question. I do not know where it goes, but it is long so I assume it goes to the passenger side.

[72c20customcamper]

Looks like a fuse holder connection. My aftermarket ac has one inline to the blower motor

[kwmech]

Is there 12v there either batt or ign? Looks like a bullet plug-maybe for the cig lighter?

[68 C10 Driver]

Originally Posted by 72c20customcamper

Looks like a fuse holder connection. My aftermarket ac has one inline to the blower motor

Being a black wire I am guessing this is a ground of some sort that connects to a post maybe? I do have an orange wire that goes through the firewall for the blower motor.

[68 C10 Driver]

Originally Posted by kwmech

Is there 12v there either batt or ign? Looks like a bullet plug-maybe for the cig lighter?

I do not have the battery connected yet, not that far along. The cigar lighter has a red wire that heats the element, ground is achieved through the mechanical connection at the dash.

I am just real stumped as to what this wire connects to. The only thing I do not yet have installed is the radio...radio ground?

I appreciate the responses.

[LockDoc]

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Grasping at straws here. Do you have this ground wire? It is the ground for the cluster. You could use a Multi-Meter (OHMS) and see if your wire connects to that space on the cluster connector.

LockDoc

[dmjlambert]

That connector is interesting. I would like to hear the end of the story. Specifically where does the other end of that wire go. Trace it through the wiring harness by looking what direction it goes into the bundle and you can probably gently tug on the wire to see or feel what wiggles on the other end of a wrapped run, and check out the color of the wires on the various connectors. Use an ohm meter if necessary.

You may be able to contact the manufacturer or vendor of the wire harness and find out from them.

[Tmend]

Does the other end go to the fuse box? Is this an m&h under dash harness?

[Sheepdip]

Just curious...Your new harness kit did not come with a fuse block/wiring diagram? I've installed at least a half dozen of those over the years and they all had diagram/instruction sheets provided. Then it got even easier on the last one I did on my 40, each wire was printed about every 18" or so with what it went to.

[Bigdav160]

Looks like 1/2 of a fuse holder. Related to the amp meter possibly?

[68 C10 Driver]

Originally Posted by LockDoc

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Grasping at straws here. Do you have this ground wire? It is the ground for the cluster. You could use a Multi-Meter (OHMS) and see if your wire connects to that space on the cluster connector.

LockDoc

The cluster ground is connected, that one is easy as it has that odd clamp connector. I will look for the schematic that came with the harness. I guess I got ahead of myself by wrapping the harness in harness wrap...I really don't want to cut that open.

I guess I will chase that wire down using my multimeter.

Thanks again guys!

[68 C10 Driver]

Mystery solved, the wire in question is from the under dash air conditioners wire to the binary switch (back in the day it went direct to the compressor.

I just had to unravel the harness tape to follow it. Thanks to all that offered their thoughts and guesses.