Oil pressure gauge

[67Vega]

Hey guys, I got a 67 gmc c1500 with a 250 I6. I'm updating all of the wires in it along with the dash cluster. The old dash wasn't working so I'm updating it to a digital one. Only problem I'm running into is that I can figure out how to locate the area I'm supposed to install the oil pressure sensor, and how to run any wires to the dash cluster. If you guys know how to do this, I would greatly appreciate any help because I'm kind of lost on this. Thanks in advance.

[ray_mcavoy]

Welcome!

The oil pressure port on the 250 inline-6 is located on the passenger side of the block, right below the rear side cover. Right above (and slightly rearward) from where the dipstick tube goes into the engine.

If your truck originally had a warning light cluster with an oil pressure warning light, there should be an oil pressure switch installed at that location on the engine. You'll have to unscrew that old pressure switch and replace it with the sending unit for your new gauge cluster. The old wire that used to connect the oil pressure switch to the warning light can be re-used to connect the new sending unit to the new gauge. Or if that wire is bad, it can be replaced with a new one, following the same routing.

If your truck originally had the optional gauge cluster with a mechanical oil pressure gauge, there will be a section of 1/8" OD steel tubing leading to a fitting at that location on the engine. Again, you'll have to unscrew that line & fitting to install the new sending unit. In this case, the wiring harness won't have a pre-existing wire you can re-use. But running a new wire isn't that difficult. With a pair of male & female Packard 56-series terminals, you can run the new wire through any empty cavity in the firewall bulkhead connector and bundle the new wire in with the rest of the harnesses.

[67Vega]

You sir, are a God send. Thanks for that. Now I gotta actually run the rest of these wires and finish this job.