Oil pressure gauge not working on MK wagon

[Mr Toad]

Hello,
My oil pressure gauge goes up with the ignition switched on and falls all the way back down when the engine is running! any suggestions as to what the problem is?
Toady

[G-ForceCrew]

Hey Mate, Just have a real guess for yah. if there is two wires comming from the oil pressure switch one is for the oil pressure light and the other is for the oil pressure gauge. It wont damage anything to swap these as long as what they are. Voltage outputs from both leads can be checked. the light is 12volts from terminal on lead off oil switch to batt + eg grounds to the block, 12volts flows when no oil pressure when key on no motor running, voltage open with no circuit when oil pressure limit is met by oil switch. What engine , what mods , km's. Remote sensing kits do back up the factory ones.

Mate you need to get this fixed. If you have no oil pressure now would you know. Small can become very big with no oil pressure.

Good Luck Kel

[Robo]

Would of thought oil pressure only existed with engine actually running, and for a reading without engine should only mean guage is getting power with engine off.
a short some where and seeing this is a small circuit shouldn't be to hard to find.