problem after problem= sledge hammer

1987 MK1 Golf Cabrio 1.8 Gti (DX Engine)

my car has been off the road for about 4 months due to some starting issues, i have replaced the starter motor with a new one, fixed the air leak which was causing idle issues and i had to do some rewiring aswel. now all was well when i turned the key car started first time, all electrics work perfect and idle is perfect. but and it is a big BUT, i took the car for a quick spin an quick the spin was i got about 50 yards from my house an the oil light came on along with its mate the annoying buzzer. now the car is just under full with oil so no problem there, i have read through a load of forums about this problem an they all say about replacing the HIGH pressure switch as they are a common problem so i have within the last couple of days replaced the high an low pressure switch. now the car never had this problem before its only had it since its been off the road an put back on 2 days ago, the switchs are from GSF  and it is High pressure switch 1.8 bar (white body) an Low pressure switch 0.3 bar (blue body) is this correct if so what is my next port of call to sort this problem out as i am close to taking the roof of it and renting it out as skip.  any help is really appreciated.

Before blaming the switches, and especially as the car has been sitting for a while, I would definitely get the oil pressure checked to make sure the warning is not for genuine low pressure.  Oil pumps are not too expensive and relatively easy to replace.

It may also be a fault on the printed circuit in the dashboard.

You can connect it to earth and it will stop, but if doing this you'll need to fit an oil pressure gauge to warn you of any problems in future.

my derv oil warning kept coming on,so i ditched the low pressure sender and fitted a vdo 10 bar sender into the head,i show good oil pressure all the time even on a hot engine,cant beat a gauge  :wink:
Bert

thanks for the replys, i have replaced the oil pump, high and low pressure switch, oil filter, oil and sump gasket. i still have the same problem anyone know were i can get a decent oil pressure tester kit?   :dontknow: