OIL PRESSURE SENDER TEST
All NVU pressure senders are 240-33 ohm. That means the resistance to ground is 240 at zero and DECREASES as pressure INCREASES.
TEST:
Disconnect the sender wire at the sender. You cannot measure the resistance with the gauge connected or you will also be measuring what is in the aguge and you will have a faulty reading.
Using a multimeter set on OHMs measure the resitance to ground with the engine OFF. Power does not need to be on. With ZERO PSI you should see roughly 240 ohms give or take 10 or so.
Start the engine, the resistance should drop as pressure increases.
Perform the same test at the gauge wire termination while disconnected from the aguge, this will confirm the same reading at the gauge termination.
Sender starts at 240 and resistnce moved down as pressure increases> sender good
Sender does not operate as above> sender bad contact NVU customer service for assistance, p-lease have code PRESSTEST! available
0-100 PSI sender curve:
0 PSI 240 OHMS
14.5 PSI 210 OHMS
29 PSI 180 OHMS
43 PSI 150 OHM
72 PSI 90 OHMS
103 PSI 33 OHM