[urq] Oil pressure switch : why 2 ?

[Louis-Alain Richard]

Only two cars in my driveway, but so many questions...

Eric's car has two (2) oil pressure switches on the driver side of the
block; one white, one black (or brown). However, only one is connected
to the blue-black wire. And I can't find another wire for the other
switch. 

Bentley shows only 1 switch, a 0.3 bar unit, on track 179. Was this
second switch installed only to plug an empty hole ? 

Louis-Alain