Oil pressure light stays on
 

I posted this question about a year ago and still cannot get it figured out. I have 01 Ford with an 03 cummins in it. I am not getting any reading from the oil pressure gauge and the light is always on. I've driven the truck about 25K miles. So I know I have oil pressure. When turned off I have an open circuit at the sending unit. Which is mounted on top of the oil filter housing. I have zero ohms at the sending unit when the truck is idling. Any suggestions would be much appreciated. Thanks in advance.

Update. I took the dash out. The wire connecting the sending unit is white w/red stripe. There is one that connects to the garage cluster. An ohm meter reveals a closed circuit when the truck is running. Does that mean I have a bad gauge cluster? Oh! And the sending unit is working.

Am not sure where your sending unit came from, is it the one that was meant to work on that particular truck? By your description it sounds like an on/off switch, instead of a sensor that provides a variable resistance according to changing pressure. I am not sure on that truck exactly what voltage range the gauge is designed to work with; possibly somebody sold you the wrong sender. I am assuming that the gauge has never worked since the engine was installed.

Hmmm.....I bought the sending unit from Carquest. It's the only one I could find to fit the connector. It's a single wire set up. I'll make some calls in the morning.
Thanks.

Unplug the wire from the sender then ground it to the engine then turn the key on and see if the gauge raises, if it does then you have a problem with the sender, if it doesn't you have a wiring or gauge problem.

Well. Based on that. I either have a bad gauge or wire. Since I put an ohm meter on each end of the wire and go a complete circuit, I'm guessing the gauge is bad.
I'll install another one and report back. Thanks!