Alarm At 2600 RPM

[dhansen]

I have a 1999 Sea Ray 230 BR with 454, 320 hours. Launched this Spring and all running well until I get above 2600 RPM. Above 2600 RPM alarm starts sounding and won't shut off until I shut down the boat and restart. Alarm won't sound idling. Temperature (170 degrees), Oil Pressure (40 PSI), and gear lube look good. My mechanic noticed the water pump was on it's way out (it was the original), so we replaced it, but the alarm still is going off. The voltmeter is hitting 16+ at this RPM, so I am thinking the alternator may be going out and is tripping the alarm system. Any ideas?

 

[Nehalennia]

16V is high. How are your batteries? They may be the issue to cause the alarm. Also, check the terminals on your alternator. I had a similar problem (on my '99 230OV 5.7EFI/Alpha I) with my batts going low to find that even though the voltmeter on dash looked good. The batts were running low and the alarm would go off and the radio flickered. I had a bad connection on the alternator. You could not visually see it, but under the plastic terminal the wires were arched and ready to break. I striped back the jacketing to good wire, re-terminated it, replaced the batteries and I was good to go.
Good Luck.

 

[dhansen]

Thanks for the response. Took it out again tonight with a voltmeter hooked to the battery leads to see if my voltmeter gauge was giving me the right reading. Looks like it might be too high as my voltmeter was reading right where it should be...14.7. The alarm sounded again and I didn't notice any spikes in voltage. I took it back into the slip and tried to reproduce the problem by revving it up to 2800-3000 RPM in neutral. I couldn't reproduce the alarm, so I further narrowed it down that the alarm only happens when it is in gear and planed out. Any other ideas? I am going to head back to the drawing board for the next couple of days and head back down to the boat on Friday to take another crack at it.

 

[dhansen]

Did more troubleshooting this weekend and have pretty much narrowed it down to the oil pressure sensor. However, not sure where to find the oil pressure sensor. I have a remote oil filter on a 454 MPI Big Block. Any ideas? My mechanic told me to follow the piping from the filter back to the engine and it should be on those.