Oil Sensor Gauge type testing

[HS 69 Charger]

Now that I have my Dash all restored and calibrated I am going through the sensors to validate each plus the wiring. I have the Temp sensor all squared away plus its wiring resistance checked. Now am on the Oil Sensor. Wiring and ground are testing good but sensor is a bit erratic.
Current one reads infinite (open) at no pressure.
Kicks in about 10psi at 30ohms
Peaks at about 15ohms at 80 psi but actually a bit earlier at 70psi.
Since the gauge is marked at 0 to 80 and calibrated at 70ohms = 0 and 10ohms = 80 that is what I expected from the sensor. Or at least reasonably close.
I got a new one from Napa. It reads infinite (open) all the time so that became useless as a second test. I will go back tomorrow to get another one but while I'm waiting, I would like to confirm what should I see on these sensors.
I saw another post that said 9 to 72ohms which is the range I was expecting. Just looking for confirmation of my expectation as i get another unit from Napa.

Thanks for any help,

Martin
69 Charger 383 SE

 

[dadsbee]

Repro stuff is junk 50% of the time... at least you read open vs closed that will fry your gauge like mine was. I test every one of them before install as shown here...
1969 Dodge Super Bee Coupe Restoration

 

[HS 69 Charger]

I'm didn't even reach 50/50.
All 3 were Standard Motor Products also known as Echlin (per SMPs website)
Napa
1st unit was open all the time.
2nd unit started as open and about 10psi changed to about 215ohm. Then never changed as the pressure went up.
OReilly
3rd unit works, mostly. Starts at open then about 5-10 psi chgs to about 33ohms and ramps up to about 18ohms at about 65psi

Interestingly, my original started at infinite at no pressure jumped to about 30ohms and then ramped to 15ohms at about 70psi.
My original had more range than even the best "replacement" found.

So I stuck the original back in. It was actually the "best" with the best operable range. And it was about 35psi at 23ohms.

I was underwhelmed, but time to move on. Lost way to much time on "replacing" with my original with my original.

I was really hoping to get a full range so that at no pressure it was nearer to 70 ohms and not open.
Curious if OEM part went to full OPEN at no pressure or indeed started near 70 ohms?
At the very least would it ramp from near 70 to near 10?

Hopefully, this might help someone else not chasing to far down the rabbit hole.

Martin

 

[72RoadrunnerGTX]

 

[HS 69 Charger]

That's really cool to see the actual tool originally used to calibrate the gauges. I also note that each gauge is tuned slightly different on the plus/minus target. Definitely, great info.

To clarify on my question, I have already done the gauges, although not with that exact extra "+/- tune" information, they are pretty well set up.
My question lies with the sender units. As an example, it is noted the Temp sender is actually about 250ohms at ambient. Similarly, I am curious what the OEM Oil sender put out at no pressure and if it truly went all the way to 10ohms at 80 (the top mark on the gauge). Just because the gauge is set up for a full range doesn't really mean the sender has the same full range or like the temp sensor could actually be broader.

I still think the calibration tool label is really cool to see. Thanks so much for sharing.

Martin