Oil pressure warning light on - Bernie, the bolt, please?

Ok, you need to be as old as me at least to remember Bob Monkhouse and the Golden Shot and that catchphrase.

In this case I am applying it to my sodding Disco just as I re-started it after walking the dog this pm. Warning light came on, so mindful of dire consequences of a lubrication failure etc brought about by the oil pump sprocket bolt coming out, I turned the engine off immediately.

Haynes says it could also be:

Low oil level - it isn't, I checked
Worn engine bearings - f'knows
High engine operating temperature - nope, all normal
Oil pressure relief valve defective - no idea
Oil pick-up strainer clogged - ditto

And of course, presumably the oil pressure switch could have failed

Just did a 700 mile round trip last weekend and thank God no problems apart from the *six* amigos - see my other posts. JSF Norwich have already diagnosed a SLABS ECU earth fault there and the car was going in tomorrow to have this investigated. Now it looks like I will have to get the effing car recovered from where I left it!

And to think I sold a 2008 Kia Cee'd with three years warranty left on it for this!

I can't see how I can get to the pressure switch from above to test its resistance - is it possible and what should the resistance be if it's working properly? It's under the exhaust manifold, isn't it - near the oil filter?

Anyone got any ideas or just some consoling words?

Thanks

Resistance! now that is advanced for an oil pressure switch, normally they contain a set of electrical contacts, diaphram and a spring set to what ever psi, any one the three componants can fail and give you the fault you have.

Easy to change five mins or so, if you can reach it.

its just a switch either on or off.... the ohm meter needle either moves full scale or dont move at all