Oil Pressure Gauge Testing

Since I put the '6 back together the oil pressure gauge has not worked. I have checked the wiring (OK, THE wire), wire seems fine, the needle on the gauge actually jumps up just a little bit when I start it, but does not move up into the numbers - just hangs there way to the left.

I had been thinking the sending unit may have had too much paint on it (yes, I painted it when I rebuilt the rig) so I took some 200 grit and cleaned the contact but still did not solve the problem.

Is there a test for the gauge and/or sending unit?

PS: Yes, I have driven the Jeep several hundred miles with no working oil pressure gauge.

 

You have a DVM? Should read about 235 ohms at 0 psi and 33 at 80psi, with a range between.

Probably easier to check the gauge with some resistors from Radieux Shaque. Just sub some values between 200 and 30 ohms from the sender wire to ground with the key on. if the gauge moves over it's range, the sender is junk.

 

Hmmm, what is this DVM of which you speak? Digital Volt Meter? Do I use the DVM to test the gauge or the sending unit?

The needle on/in the gauge DOES move a bit. It jumps up at start-up then stays "up" but way to the left while running. Would seem the gauge is doing something, but does not get up in the "numbers" to tell me anything.

 

Well, you could use the DVM (yes, that's right) to check the sender, but it's easier to check the gauge. To check the sender, you need a source of oil pressure ... engine running... too much hassle.

If you pull the wire off, does the gauge go all the way back to the left? It should.

Do you understand what I'm suggesting with the resistors? You replace the sending unit with a fixed resistor to see whether the gauge moves properly with that resistance.