Do you own a multimeter?
The low pressure switch on ADY should be NC (i.e. with engine NOT running should have continuity with GND).
High pressure switch is NO, so should be open loop with engine NOT running.
Vice versa with engine running and oil pressure being OK (the high pressure switch may only trigger at higher rpm when oil pressure is higher than in idle).
Sorry, i have been a complete dic*head.
I have been out today with a multimeter and checked the continuity of the pressure switches, with engine off and then running.
All seemed ok.
I noticed, however, that the coolant expansion tank level looked very low, so i topped it up.
When i re-started the car, i noticed the light that had been flashing was the coolant level light, not the oil can.
So oil pressure is ok, with no leaky oil pressure switch.

Just need to keep an eye on why i had lost most of my coolant.
cheers for the help guys.
thebassman