[VetteVet]

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Originally Posted by Clint72

Alright, here are a couple pictures of what I found on the harness.
Everything looks to be correct except for the fact that there is a wire coming out of terminal 5 and it's been spliced to a green wire, then two come out of 6 but ones spliced and the other is cut.

Well yes but not really. Your plug does not show the two ammeter wires on 1 and 12, instead I see a blue wire on 12 and nothing on 1 that I can see. These two wires are not needed if the PO didn't want an ammeter and used a voltmeter instead.I think the harness on this truck was originally set up to be an idiot light harness because the black wires are missing, and had the sender wire for the temp gauge run to the cluster plug first on pin 5 and then to the key switch, instead of what the diagram shows.
The factory could have put the double green wire on the cluster plug pin 5.

When the previous owner converted to the gauge cluster, he repinned the cluster plug and cut one of the two green wires that went to pin five, and one on pin 6 and just left the extra wire loose on pin 6. The other green wire on six would go to the block sender.

The green wire on 5 must run back to the key switch or else it is grounded somewhere, because it has to be grounded to turn on the light in the cluster, if there is one.You haven't said yet.

The second green wire on Pin 5 would have to go to a second sender in the block or head to have the light work properly. It may be the cause of the light coming on when the key is on. Remember these are the ground wires for the light.

The blue wire in pin 12 was probably in pin 1 originally and he just stuck it in 12 because it wouldn't be needed for the oil pressure gauge. and the gauge cluster doesn't have an oil light.

I really appreciate y'all help!

and boog, I figured that out when buying the new sending unit, the one i put in is for gauges, thanks!