Oil pressure error p0523

[madchef]

Hi all, my 2007 crd patrol just had its oil light come on, only happens early morning ? And have a code p0523 oil switch high volts ? It’s not on now but very random, looking at which one it could be ? I have disconnected the wire from the one by the filter and the light has gone on start up and while running. I have used my tester and when the is engine is off the tester alarms (closed ) ? When engine running no alarm? Placing connector on the oil switch connector then the other on earth . What do you think ? It’s cheap for the one but $$$$ for the other. Cheers
Hope that makes sense lol