[cd1154]

When I first purchased my Tiara on the starboard engine I received the audible alarm and the light on the dash and the pressure was low but I wasn't getting any engine tic so I wasn't concerned that the pressure wasn't too low. Crusader 7.4's

I replaced the oil pressure sender and this cleared up. To be sure I teed off the port and installed a manual gauge to compare just to be safe. This issue was solved.
After digging around under the dash I did notice that the starboard Astro board was new.

My port engine is giving me a battery alarm and the gauges on both engines show low battery voltage. The Astro board on the port engine is old but I need to did  in there a little more and start hunting down a possible bad ground which I think is causing the bad reading on both gauges. The problem in south Florida way to hot to sit outside and play around with a meter in the engine compartment.

Like you said in your post I also believe the the alarm board is being triggered by the VDO gauge. I would put the manual gauge as my first step. Because you said that it is starting to happen on the other engine I started changing the way I was thinking.

Purchase the manual gauges and put them on both engines and leave them there..... forever. It is always a great, quick check when you are feeling uncomfortable.

If those manual gauges are not matching the VDO gauge then you may have your answer and may solve this issue with replacing a couple of oil pressure gauges which will become very unreliable over time.

Let me know, good luck.