VDO Oil pressure gauges

[[448]]

Anybody got any info on wiring of these gauges, which are all electric and are fitted on my boat with v**** AQ165 engines of early 70's vintage. There are 3 terminals, one marked +, one marked G, and one not marked. I could use trial and error, but I don't want to bust them by connecting them up wrong.
Cheers, D.

 

[pvb]

+ is wired to 12volt positive.
G is wired to G on sender unit.
Third terminal should be marked - and is connected to 12volt negative.

 

[[448]]

Many thanks for info. I'll look a bit closer for the negative (-).
Cheers, D.