We have a 2002 V6 Petrol S Type with 100,000 miles on the clock that has an issue where the oil pressure light glows very dimly in the instrument cluster. Oil level is correct and engine is a sweet as anything sounds great. The light even stays on when the engine is off and the ignition key is removed. Any idea's ?

 

Yes you've got an electrical fault.

Can't remember how much a new oil pressure switch costs, but if it's not too bad I would start there, unless you can see any dodgy-looking wiring leading to it.