Oil pressure sending unit question??

[BadCompany]

I have a '87 r10 and the PO swapped out the tbi for a 350 crate engine and installed aftermarket gauges. I am going back to the stock setup and have already installed a new oil pressure sending unit but cant find the wire to run it. I did find a brown wire cut off in the wiring harness but when I connected it to the sending unit the gauge still just sits pegged at 60. Any ideas???

[hatzie]

The oil pressure sender wire should be tan.

Nailing the gauge means you have a shorted sender wire or damaged gauge.

[BadCompany]

Where does the tan wire run into the wiring harness at? Is there a way I can determine if the gauge is bad?

[BadCompany]

Tore into my harness and found the wire I was looking for and followed it all the way back inside the cab. The PO had then connected the brown wire to the wires that run inside of the drivers door shorting out my gauge causing it to peg out.. Got everything rewired and the gauge now zeros out like it is supposed to and raises when I crank the truck. Havent had a chance to drive it so I dont know if it is correct. When I tap the gauge while the truck is running the gauge will start to give sporadic readings would this be a loose connection?? Thanks for the help..

[hatzie]

Drive it on a rough road. If the gauge holds don't worry about it. If it gets sporadic check the spring clips in the gauge pod/housing are making contact with the plastic printed circuit and closing on the gauge studs. Make sure the nuts on the gauge studs aren't loose.

[mikey882]

Originally Posted by hatzie

Drive it on a rough road. If the gauge holds don't worry about it. If it gets sporadic check the spring clips in the gauge pod/housing are making contact with the plastic printed circuit and closing on the gauge studs. Make sure the nuts on the gauge studs aren't loose.

This man knows his Chevys
Posted via Mobile Device

[Fan2zee]

Originally Posted by BadCompany

Tore into my harness and found the wire I was looking for and followed it all the way back inside the cab. The PO had then connected the brown wire to the wires that run inside of the drivers door shorting out my gauge causing it to peg out.. Got everything rewired and the gauge now zeros out like it is supposed to and raises when I crank the truck. Havent had a chance to drive it so I dont know if it is correct. When I tap the gauge while the truck is running the gauge will start to give sporadic readings would this be a loose connection?? Thanks for the help..

I have the same issue on my 87'... Do you happen to have details/pics of where this wire is located? I can't find it either... I see you "tore into harness", where is this harness, color of wire? And then I'm guessing this wire runs straight to the oil pressure sensor..

[hatzie]

Originally Posted by Fan2zee

I have the same issue on my 87'... Do you happen to have details/pics of where this wire is located? I can't find it either... I see you "tore into harness", where is this harness, color of wire? And then I'm guessing this wire runs straight to the oil pressure sensor..

No pics of the harness itself but here are the plugs. It's a single Tan wire that exits the harness behind the block.
Straight from the sender ---> Through the Engine/Bulkhead plug ---> Instrument cluster plug. GM circuit #31. For 1987 RV trucks. All other years YMMV.

[BadCompany]

Originally Posted by Fan2zee

I have the same issue on my 87'... Do you happen to have details/pics of where this wire is located? I can't find it either... I see you "tore into harness", where is this harness, color of wire? And then I'm guessing this wire runs straight to the oil pressure sensor..

Dont have pics but I just found the only solid tan wire that runs out of the plug in the engine bay and followed it through the harness to where the po had cut the wire and reconnected it to the sending unit.

[Fan2zee]

On the prowl..
Posted via Mobile Device