Oil Pressure Issue = Bad Sender?

[53D Scrambler]

After watching my oil pressure gauge read 20psi at cold start and decrease to 1-3psi after about 20min of driving I began to worry that something might be wrong internally with the engine or that I have a bad pickup. I bought a mechanical oil pressure gauge / test kit and discovered, much to my delight, that I had 60-65 psi at cold start and 55 psi or so after the engine was up to operating temperature. I am certain now that either my gauge is the problem or the sender is bad.

As far back as I can remember the oil pressure has run low but used to be steady at 15-20 psi and my Dad who had the Jeep since 1999 saw the same. The Jeep underwent a full restoration and the old wiring harness was replaced with a painless but I kept the original sender and gauge. Does anyone have tips for trying to get an accurate oil pressure reading with the stock gauge? Should I get a new sending unit and if so, are the typical Omix ones worth it or should I go with another generic sender that uses the single wire? Is there any way to test the sending unit with a multi-meter?

I would like to use the stock gauge if I can.

Thanks

 

[FLCJ8]

..... I bought a mechanical oil pressure gauge / test kit and discovered, much to my delight, that I had 60-65 psi at cold start and 55 psi or so after the engine was up to operating temperature. I am certain now that either my gauge is the problem or the sender is bad.
...... Is there any way to test the sending unit with a multi-meter?

I would like to use the stock gauge if I can.

Thanks

If you "T" the existing sensor in with your test gauge you can check the resistance at various pressure readings.
The ohm readings should correspond to these readings.

If the readings appear good then check all the connections back to the gauge, including the grounding of the gauge itself.

 

[53D Scrambler]

Awesome, thanks for the info. I will dive into that once I find the right T-fitting.