Hello Breezy-Pete, thank you, you are right! When disconnected, the oil light eventually shows (after nearly 20 seconds) but it's on the MFD (Multi-function display) in this Elegance model, not on the rev counter with all the other lights (where it should be in my opinion). It takes a long time, and, if there was no oil, then some significant damage could be done in that 20 seconds. Video link is below, so that others can see how it works. (The wire comes off easily in the video because I'd previously unclipped it, so I could remove it with one hand, holding the camera.) I think Skoda have tried to be too clever here, and an on/off switch would be adequate. So it's possible my old switch is fine. By the way, the new one was a proper Skoda one. Thinking this through, my test doesn't actually prove the pressure switch is working, merely that it's providing a signal all the time. To test it more, and prove it drops the signal when there's no oil pressure, I'd have to unscrew it, re-connect it and then run the engine with it unscrewed. But I think I'll leave well alone now. Thank you for your help. Video link: https://youtu.be/Ae1Ofbnhhtk