What is it?

[Will49]

Having taken off the airbox to see what is there ive found a sensor/sender unit screwed into the block between the starter and the dizzy when looking side on.
Ther are two spade connections on it but only one white wire connected. I can't find it illustrated in the parts manual so any ideas what it is?
If its an oil pressure sender then thats odd as my oil guage works.
Thoughts please

[Hawaiis0]

A photo would help
Here's my SA engine as a comparison

[Tanz]

That is the oil pressure sensor. Only has one wire as body acts as an earth. Guess it is common to other cars that require 2 wires.

My replacement only had one connection post

[Will49]

I agree a photo would be best.
Still waiting for my computer guy to set up the secondhand laptop for this purpose.
Thanks for the clarification ...it just looked odd with only one spade being connected.

Having taken off the airbox ive noted that the vac pipe going from the crankcase breather valve to the cold enrichment valve is crushed which cannot help the running on an SA.
To replace this it looks like back carb off but maybe that might be a good call and replace the "O" rings which might be a leak area anyway.

[rbgosling]

Worth checking the wiring diagram, but I think one spade is for the gauge (gives a continuously varying resistance with oil pressure), and one is for the warning light (either on or off). I think both spades have wires connected on my car. That said, my car was consistently reading somewhat high, until recently when it stopped showing any reading at all, so there's no certainty mine is connected up correctly either...