Why does my Monster 620 oil light stay on after a wash?

[uglytruth]

I recently got this 2006 Monster 620 and after fixing the fuel pump wiring thanks to some tips online, the bike was running great until I washed it last weekend.

Now, the oil pressure warning light stays on when the engine is running and I am confused. I checked the wire at the sensor for water, blew it out with compressed air, and cleaned the connections, but the light still stays on. I know the light itself works because when I grounded the wire, the panel light came on, and when I ungrounded it, the light went out. I also tested the oil pressure switch with a test lamp and a multimeter and those tests show that the switch is operating correctly... it completes the circuit when the engine is off and opens it when the engine is running, which is how it should work. But when I plug the wire back into the instrument panel, the light stays illuminated while the engine is running, even though my external tests say the switch is fine. Could this be a simple wiring short somewhere else that the wash exposed, perhaps near the dashboard or a different part of the harness, or is it possible that the instrument cluster itself is faulty and misinterpreting the signal?

 

[icec0ld]

Not cool at all. So the issue now is between the switch connection and the instrument panel. Water ingress from the wash can easily cause a slight short to ground in the wiring harness, perhaps where it runs near the frame or where the insulation is worn, that would keep the warning light on despite the switch being open. Better to closely inspect the wiring path from the sensor up to the dash for any chafing or wet connectors that might be bridging to the frame metal.