What is this relays function?

[dar636]

Hello-

This relay is in the STBD engine room. Same relay in the PORT. The STBD relay just started chattering at idle after a days running, it stops if I bump the throttle up (less than 25 RPM). I do not see any indication on the gauges other than the STBD engine oil pressure is at its lowest point of the day, but just above the lower limit, 20 psi.

Is it part of the alarm system, ready to sound the low pressure alarm?
Is it a OEM system?
Does anyone have wiring diagram?

1976 58' YF with DD 871TI's.

Thanks-View attachment 25937

 

[Sonic Boom]

Did you figure it out?

One of my dad's 871's has the same relay and the other engine doesn't. The only thing we can figure is it's part of the external voltage regulator? (the other engine without is was updated) Or a reverse current cut out relay so the alternators and battery chargers don't try to charge the batteries at the same time?