Had to rewire part of my harness a few months ago due to the battery the PO had clearly neglected (melted). And today I'm tinkering around trying to get my tach to work. Random leftover wire which reminded me about the extra socket I couldn't connect.
Any ideas? Thanks gents.

 

It's a four plug socket, two vertical to horizontal. Can't unload the other pics from the app.

 

Did you download the FSM for a 1983 pickup? It should help with your wiring problems. Do a search for it.

 

I do have it, but have yet to identify what connector it is and what this yellow wire is for. The un-identified connector has two black with yellow (stripe), one solid black, and one yellow.
Unfortunately a large section of the harness got charred up on the pass side when the battery popped, that's part of the problem.

 

Look at page 15 of my build thread. I stripped my harness of all emissions wiring and that plug was scrapped in the process. If I recall correctly, that plug ties into the CMH (Cold Mixture heater under the intake manifold) relay (on the passenger side wheel well - see page 15 of my thread), battery, ignition power and emissions computer. If you are running without emissions it is definitely not needed. Even when I had emission on my engine, that plug was never connected. I would follow the wires back to the sources and see where they tie into.

If you want to get a more definitive answer I would ask Don (suncomb on here). He knows damn near everything about the wiring of these trucks. I'm sure that he would be willing to give you some advice.

 

that would explain why i couldn't find the other end! I need to get around to actually removing all the emission components versus them just sitting and being useless.
i'll tear down that side of the harness this weekend I suppose. maybe i'll finally get my tach to work in the process!?

 

Just a FYI that side of the harness has a whole lot of emissions wiring running back to the emissions computer on the driver side kick panel. Some of the emissions stuff runs from the computer to the sensor or switch and then to the ignition switch so tracing it one way doesn't get it all. I have found that the easiest way to remove emissions wiring is to start at the computer and work your way away and then back so that you get it all. You'll have a decent pile of wires when you are done

 

does it makes removal significantly easier (significant meaning counting the trouble of removing said dash, which ive never enjoyed doing on any vehicle) if i take out the dash? or will i be able to get it all out with it in?

 

It is a lot easier to strip the emissions wiring out while the dash is out. Leave the seats in though, it's way more comfortable to sit in there! LOL When I did mine I left the harness in the clips behind the dash and unwrapped all the tape. I removed what I needed to and then re-wrapped the harness with GOOD electrical tape (don't skimp on the tape - it makes a difference) while it was still in the clips so that I could wrap the harness tight while still maintaining the "shape" of the harness. Keeping the harness in the clips also helps you keep track of what wires come off the harness to various components. It's not too difficult, I could have done mine in an evening if I didn't have other stuff going on.

 

You sir, are a genius.

 

I do what I can...