Oil pressure gauge shows zero

[zzb3886]

Hi there,

About a week ago, the oil pressure gauge in my 2000 XLT showed zero oil pressure. I was sure it wasn't actually zero, because I was able to continue driving for 20 miles without a problem. Thinking maybe the oil pressure sensor was the problem, I replaced the oil pressure sender unit closed to the driver side wheel. But that didn't solve the problem. I measured the resistance of the oil sender, it did drop to a couple hundred ohms after turning on the engine. I suspect it is a wire or gauge issue, because when I connected the pin in the connector to the ground, the gauge still said zero. But now I'm having trouble testing the wire. Where does that dark green wire go into the dash board? If I am able to find it, I can hook up another wire to see if it works. Thanks!

 

[mechanix]

I have seen in the past where there has been SO much sludge and gunk in the engine that the passage to the oil pressure sending unit has been plugged. I would first make sure this is free of debris and also a double check with a manual gauge wouldn't hurt. Just so you are not chasing down wires and it turns out to be a problem in the engine.


Eric

 

[zzb3886]

Thanks, Eric. But I did connect the wire to the ground, which is equivalent to having a perfect sender and proper oil pressure, from the gauge's view. And gauge still didn't give a proper reading. I'd like to think about it before taking the sender off, because I don't have a pressure gauge here.

 

[mechanix]

Looks like you will need to trace the wire back to the instrument cluster and try to find the shorted wire, maybe you burnt the copper in the back of the cluster. This is only speculation, I haven't seen a newer cluster, only one I saw was an older vehicle it had a copper a ribbon that was burnt in two. I would check the bulk head connection that goes into the cab, from there move on up the wire until you find the problem. Or you could pull the cluster out and check the resistance in the wire from the sender to the gauge. That would probably be the best.



Eric