Any suitable relay and two diodes, one from each pressure switch.
Or, both pressure switches in parallel.
It depends on where you source your current.

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Ohm's law
Not just a good idea;
It's the LAW!

WAROSS
The supply is coming from a battery 1 each for each engine completely separate supply systems.
Can you draw a schematic and parts needed?
This is what I had figured so far.
NO switches in the oil circuits of each engine.
Power supply from the local battery fused to one side of the OP switch and flowing to the sense of the relay. Actuating the relay to the load 15a of the relay to the fuel pump.

I think this is correct and stand to be corrected if you will. I also need the single pump to turn on with either engine running. Is there diodes to be installed?
Thanks and can you draw the schematic.

2 engines, 1 pump, all 12 v.

Marine professional

Engine one;
Battery 1, to fuse 1 ,to diode, 1 to relay, to common ground.
Engine two:
Battery 2, to fuse 2, to diode 2, to relay, to common ground.
Pump source. to fuse, to relay, to pump, to ground.
OR
Battery 1, to fuse 1, to relay 1, to ground 1.
Battery 2, to fuse 2, to relay 2, to ground 2.
Pump source. to fuse, to relays 1 & 2, relay contacts in parallels, to pump, to ground.

--------------------
Ohm's law
Not just a good idea;
It's the LAW!