V6 OMC 'NO OIL ALARM' won't sound - troubleshooting help wanted

[at100plus]

1987 225 Evinrude. I have run the engine several times now on premix. I have twins. The starboard engine started sounding the no oil alarm after about 3 to 5 mins of running but the port motor won't sound the alarm. I have run it up to about 8 mins on the muffs. I wanted to verify it was working before I bleed the oil line and connect it to the VRO pump.

Note: It chirps the alarm when I turn on the key and the tan wire grounded DOES sound the overheat alarm and I have put a continuity tester on the tan wire as it makes its way thru the red amphenol cable to the VRO pump and also out of the small black plug up to the top of the engine somewhere under the flywheel. I checked and cleaned all related ground wires.

I think all wiring is good, it must be a sensor or module that detects the no oil condition?? Perhaps I'm just not running it long enough?

If I can't figure it out, the boat is going in the water Saturday I figure I'll run it on premix for like up to a half hour and see if it goes off before I connect the oil line.