Hi Ian
Not my strongest area but my understanding is cars with gauges have oil pressure senders that have a variable resistor that alters current as oil pressure increases/decreases and interface with the gauge.
Alternatively, for cars without gauges a simpler level/pressure switch is used. It monitors the oil pressure and turns off or on a warning light.
On the duratec I would surmise the Morgan stock engine had the simple sender (with the green connector). But the more ‘sophisticated’ silver pressure sender was added to complement the instruments. But, the original sender was retained (though not connected) possibly to aid “plumbing”.
I may be totally wrong, of course.
I’m Interested to know whose pressure sender is in use! Probably Caerbont.
