Common oil light problem

[bigbroony]

The oil light came on in my 2.0l Corrado last week.In the absence of any nasty smells or noises I'm hoping it's an electrical fault.I'm aware that the 2 switches are of different values and I've just replaced them this morning to no avail.
However while surfing it's occurred to me that even the"low" switch is rated a bit high at about 1.4 bar. The "high " switch is approx. 1.8.Further surfing has revealed that the low switch should be 0.3 bar.Is this correct?I've ordered one anyway as it's worth a try at £4.

Cheers Alan.

[Crasher]

Presumably this a 9A engined 2.0L 16v, not an ADY 2.0L 8v? The low switch was 0.3 bar and brown, it is now 0.25 bar and blue, VW part number 028 919 081 H and has the blue/black wire going to it. The high pressure switch is 1.8 bar and white, VW part number 056 919 081 and has the yellow wire going to it. These switches work the opposite way around to each other, the 0.25 bar switch is pressure applied to BREAK contact and the 1.8 bar switch is pressure applied to MAKE contact. Below 2200 rpm, the blue switch must be open circuit or the light will flash but the beeper will not sound, so this can be replicated by disconnecting the switch and leaving it open. Above 2200rpm, the dash must see the blue switch open circuit and the white switch as a closed circuit; this can be replicated by disconnecting the yellow wire and connecting it to a good earth. With the blue/black wire disconnected and the yellow wire earthed, there should be no dash warnings at all, if there are it is either a wiring fault or a faulty dash.

[bigbroony]

It is indeed a 9A.Further investigation tonight has led me to think it's faulty wiring or dash.
With the ignition on but no engine, there's no oil light.When the engine is started the light flashes.With the blue wire either disconnected or earthed and the engine on the light goes out.Disconnecting the yellow wire with the engine on still has the light flashing.
This surely signifies something, though what that is I have no idea.I imagine a faulty dash isn't a good thing ! !

[Crasher]

If there is no oil light with the ignition on, earth the blue/black wire, the light should flash.

[bigbroony]

It's raining heavily outside at the moment mate, but I'm fairly sure it doesn't flash.That being the case, what's the likely problem?

Cheers Alan

[Crasher]

If it does not flash with the ignition on and the blue/black wire earthed you have a wiring or dash fault, both of which are not common issues. If it was with me and found it did not flash, I would pull the dash and check the continuity of both oil pressure warning wires up to the dash. If these proved to be OK, then I would assume a printed circuit fault. If your car is a pre 93 then the board is no longer available but that for the 93 to 95 is in theory still available from VW but at a rather shocking price of around £350.

[bigbroony]

That'd be just my luck.Fortunately I know someone with a spare unit.I'm not sure what vintage but I'll pop round during the week.

[bigbroony]

Praise be !I fitted the correct switches and scientifically shoogled the spade connections.Everything is now ticketyboo.Not sure which operation did the trick and don't much care.
Thanks for your help, Alan.

[bigbroony]

Light's come back on again. But it flickers and stutters so I'm sure it must be an electrical and not pressure problem.I know someone with an external gauge so that's the way forward I guess.