Weird alarm-5.0 Merc

[pau hana]

the boat- 2002 2359 Trophy with 5.0 MPI Merc with Bravo 3 drive.

Had the boat out yesterday, and for about 2 hours, all was well. On the way to another fishing spot (4200 rpm), the alarm horn sounded- oil pressure was good, temp at 175?- but the voltage meter was showing about 11 volts. Slowed to 3000 rpm, and the alarm went way- until I attempted to use the trim tabs; then the alarm went off again. Release the tab control, and the alarm shuts off.

Could the alternator be going out, and setting off the alarm?

Kicker engine was added to the boat recently (+ to the common post on the switch, - to the battery bus).

 

[Don S]

Re: Weird alarm-5.0 Merc

1. Check your battery connections. With MPI, wing nuts are a no-no. use regular nuts and a wrench. The connections must be tight and clean.
2. Check the alternator output with a DVM (Not the helm instruments).
3. With a code reader, you could probably find out what set off the alarm.

 

[nailem]

Re: Weird alarm-5.0 Merc

check the belts or belt tention. maybe at high rpm the belt is slipping?