The vehicle is a 2003 Ford Explorer EB with the 4.6 V8.I figured it was the sender. I replaced that and checked connections. Still "gauge" reads zero. Removed sender and used air pressure to check the sender (off the vehicle)----sender OK. What else could the problem be? I've got oil pressure as I driven it 100 miles with the zero reading and it runs fine without any lifter noise etc.Anyone else run into this?[/align]

 

just curious is there any way you can used compressed air to check the unit while its still hooked up to the cars wiring harness that way if the gauge is still at zero inside the car ,,,it may just be in the gauge itself or the wiring from sender to gauge. Id deffintently find out for sure what it is as soon as possible even if you do got oil pumping at the moment, that doesnt mean it couldnt stop at any moment and you wouldhave no way of knowing till the engine gets loud and chattering ,,thats not good.. hope you get it figure out soon thats got to be a uncomfortible feeling.

 

The switch just grounds when it sees pressure. So I turned the ignition to run (didn't start the engine as the oil filter was off), got the low oil pressure warning, and then grounded the lead to the gauge. No change in the gauge reading. So I figure I have a gauge or broken wire. I also checked for voltage in the lead to the sender with the ignition in the run position but no voltage either.

I guess the next step is to figure out how to get the instrument cluster out. If the gauge is putting out voltage to the wire, then I'll just run a new wire to the sending unit. I also think that, before I quit, I'm going to install a real working gauge!!!

 

UPDATE: I bought a service manual and electrical wiring manual off ebay. With the info in them, I took the dash apart and ran a separate wire from the oil pressure sender to the instrument panel. Everything now works as it should. Must have been a break in the wire or a bad connection in one of the 2 connectors between the sender and the panel.

Oh yes, I added a real gauge while I was waiting for the manuals to arrive, so I now have the best of both worlds.

 

My 01 Explorer does the same thing when it's cold. The guage reads zero and the check guage light comes on, but as soon as it starts to warm up, the guage jumps up to normal. I've checked and I'm still getting pressure, but the guage doesn't work. I'll have to check the wiring.