oil pressure Gauge no working

[Vmanmopar]

Ok i have a 69 barracuda i'm working on and i'm down to the last little items. Right now i cannot get the oil pressure gauge to work, i have changed the sender, checked the wiring, replaced the dash gauge (rally dash) and still nothing. The engine has oil pressure 35 PSI with a mechanical gauge i hooked up as a temporary check.

The Gas gauge, amp meter, water temp and dash lights all are now working. I did not think the volt limited would be an issue due to the fact the other gauges are working. Any ideas?

 

[barracudakid]

circuit board?
check power to gauge

 

[KitCarlson]

It should be easy to test with a mult-meter.
Seems you know the circuit, ignition supply to limiter, gauge, sender and ground. It is a series circuit, an open anywhere makes it not work.

While the other gauges work, the limiter circuit branches to other gauges out so it could be a circuit board trace, loose connector pin on board, or other connection. Gauges typically get power in key accessory position, so use that with volmeter, check sender lead, if no pulsating voltage then you have narrowed down. If there is voltage, then it could be sender, or sender ground. If teflon tape was used at sender, it can insulate sender from ground. It is real easy with power off, do continuity test, sender case to engine.
The sender has resistance that varies with pressure, but easy to measure, pull sender connection, test sender terminal resistance to ground, it might be about 75 Ohms with no pressure.

While visible inspection and part changing is used by many, the use of a multimeter is a time and cost saver. It can help focus where to work. It can be your friend at all times. The gauge has continuity, it can be measured might be about 20 Ohms. Follow all traces and connections, verify.

 

[RedFish]

My best guess, loose contact pin on circuit board. Oil gauge signal is the only gray wire in that round connector. If that contact pin is loose/broken, you can try solder board repair or simply cut the wire out of that connector and route it directly to the sender side of the inst'.
Ring terminal, toothed washer, and nut just like the ALT' gauge has, installed on top of the OEM speedy nut works just fine. Not all inst' panels have printed circuit boards. Instead, every wire is attached where it terminates.

 

[Vmanmopar]

Thanks all, electrical is not my strong point sometimes, dash was out to fix other things so it was convenient to replace the gauge. I;ll try some of this and see how it goes.