Oil pressure "lets get the definitive answer here"

Hi all

this problem has been talked about but having read through the posts I think the exact ins and outs are not covered enough for me to correct my problem.  
And I know for certain oil pressure is fine as fitted gauge directly

The Problem
Oil pressure warning light and Buzzer comes on when engine reved above 2500

there is no oil pressure warning lamp flash even when ignition just turned on and engine still off.

What I've done
1stly  I have earthed both oil pressure switches with ignition switched on and still no flash of oil pressure lamp in dash so I suspect lamp is not getting 12 to one side atleast.

with engine revved above 2500rpm and left to idle (buzzer and oil light on)
tried removing both oil pressure switch connections and even earthed them

both of these attempts to resolve have failed.

Thoughts to resolve from other posts

some say circuit board at fault but does not say precisly what to do to disconnect it as I don't mind this option as gauge is fitted.

some say provide another earth to dash clocks but not sure which wire so that I could even connect a simple wire to diagnose this is the fault. others say this wire has to go into the Board somewhere?


So what should I do

your advice is greatly appreciated.  I feel I have illiminated the pressure switch senders from the problem as I have removed connections and tried earthing direct. via wire from battery to each wire under bonnet.

sincere thanks to all replies

Paul







 

checked both pressure switch terminals whilst disconnected and there is 0 volts to the oil filter high pressure switch and only 4.9 volts to the low oil pressure switch on the side of the cylinder head with ignition on only.

cheers
Paul