Strange oil pressure gauge issue

John Scoggins

TJ Enthusiast
Joined
Oct 23, 2018
Messages
528
Location
Houston, TX
Been chasing the oil pressure gauge dropping to 0 every so often issue. I know it is an on off gauge, 6 psi and above gauge in center. I have replaced the sending unit (mopar), cleaned all connections, etc. Each time the problem goes away for a while.
Since I have to change the RMS I decided to get a oil pressure testing gauge and see what is really going on. I got 50 psi at cold start and dropped to 12 psi after warming up for 45 min, all good.
The strange issue is that the stock sending unit is out of the vehicle, obviously disconnected and I would expect the dash to show 0 psi, no the oil pressure gauge in the IC is in the middle showing it has pressure.
Has anybody seen this before, of does anybody know what signal the stock sending unit actually send when it shows 0 psi?