gnarlytoes

I purchased this '87 pickup a couple of years ago. 22RE and automatic transmission w/overdrive.

The engine had a spun rod bearing and the previous owner had pulled the engine already. I finally got around to rebuilding it last month. With the help of lurking here, a Haynes manual, and a couple of friends, I managed to figure out the wiring and vacuum lines...

Except for this one wire. It comes out of the main harness bundle underneath the intake plenum. I have it pulled out like that to take the pic. The actual wire from the harness is green wire with black stripe. In the picture you can see where someone spliced on a new plug with different color wire, so I assume it is important. It has 8.56 volts with engine running. I cannot find anything anywhere for it to plug to.

As far as I can tell, everything works on the truck. So I have no clue where it goes.

Any help would be appreciated. Here is a pic of the wire and also a pic of the truck where I drove it over to check on my dad this morning after last night's ice storm.

Romans117

Looks like the old oil pressure gauge connector or knock sensor connector. I say old because the new oil pressure gauges are just a plastic tube with oil that runs to the dash gauge.

Romans117

Nice truck bro.

gnarlytoes

My first thought also. The truck doesn't have an oil pressure gauge. Just temp and fuel gauges and the rest idiot lights. Oil pressure switch is within reach, but is connected already. Light comes on with ignition and goes off after starting engine like it is supposed to, so I assume I've got the correct wire connected to it.

I have searched the engine and compartment as best I can and everything I can find within reach of the wire is already connected.

I guess there could be another sensor or switch down under there, but I can't find anything and don't remember seeing anything before setting the engine back in. I wish I had unhooked everything and pulled the engine myself.

It's driving me nuts knowing it's not connected, but everything seems to work correctly so far.

Thanks. I think so too.

The body is straight and the only rust I can find is a little trying to start along the bed seam. I plan to paint it this summer. I've got a couple of gallons of mil-surp olive green. I had an '89 I bought wrecked and rebuilt a few years ago that I painted with it and it looked awesome. I've got some pics of it if you want to see.

gnarlytoes

If it is supposed to go to a knock sensor or oil pressure switch, should it kill the engine or at least activate a warning light if I ground it?

Romans117

Knock sensor will send a code. It's my understanding the 87 just had a light that lit up when the oil pressure dropped. I have a 86 that looks like the same body style.

87bluerunner

Does the the truck have A/C? My 87 has the A/C wire in the loom in that area

gnarlytoes

Yes, it has A/C, but it is already connected. Next day I'm off work, I will see what happens if I ground it.

DSmith87RE

Should be a male spade connector that points straight up, goes right on that. I'll check where exactly it is tomorrow I can't remember off the top of my head.