Yanmar Oil sensors

[Time2Go]

Hi Friends
While investigating a small oil leak on my
mates Yanmar 4JH3E we came across this
See Picture
I think what the PO did was tap into the
oil switch port with a bit of hydraulic hose
and attach the oil switch and pressure sender.
Never seen this before and after a search found nothing
about this modification
Anybody have any ideas what’s happening here?
Cheers
Neil

[Wotname]

Originally Posted by Time2Go

Hi Friends
While investigating a small oil leak on my
mates Yanmar 4JH3E we came across this
See Picture
I think what the PO did was tap into the
oil switch port with a bit of hydraulic hose
and attach the oil switch and pressure sender.
Never seen this before and after a search found nothing
about this modification
Anybody have any ideas what’s happening here?
Cheers
Neil

I think you are correct in your assessment.

[skipperpete]

Is your friends boat alloy by any chance? This type of connection is often found on insulated earth modified engine harnesses and that blue hose is likely not steel reinforced to avoid making a ground". If that’s a Hobbs switch in the background on the same tee fitting, the terminals could do with a bit of a cleanup.

[Emmalina]

So you have an oil sender unit and 2 oil pressure switches. I have seen this done on charge circuits so the engine doesn't go under load till the oil pressure is present. As for skipperpete's theory I don't think the system would work very well without the ground !