I’ve never had an oil pressure light

[thejinx]

So I’ve never had one. I know it’s stupid. So I’ve now decided to sort it. I’ve put in a new switch. A new bulb. I’ve grounded the wire and nothing. So how do I run a fresh wire. I have belly pans fitted so I’m lost really.

 

[sparkywig]

The engine block and gearbox ground are the earth path, the switch completes the circuit.
Have you got an 12V ignition source at the pressure switch connection? Should be a blue wire with a green trace.

 

[thejinx]

I shall check. Cheers