jdubslopro
Petty Officer 3rd Class
- Joined
- Mar 5, 2010
- Messages
- 91
A week ago took the boat out had it WOT for about 15 seconds and the warning buzzer came on steady. Checked water temp and oil pressure gauges, normal. Killed throttle immediately shut it down. popped the hatch and checked everything I thought it could be-drive lube, oil level etc. didn't find anything. Started back up kept rpm low and was fine for about half hour then when I pulled onto a sand bar the tone came on steady again, and then I noticed the voltage below 12v. I put the jump pack on and it was fine. So I pulled the batteries got them tested, one was reading 11.6v and putting out good amperage, the other was putting out 4 amps. So I replaced the bad battery, fully trickle-charged the low battery. Next time down to the boat I checked voltage, with it running at 1800rpm it's only reading 13.36V at both batteries and the alternator charging posts. Under load, I see the volt gauge drop to about 12, and drops even lower with the engine running and lifting the electric hatch. What say ye? Replace the alternator even if it's putting out 13.36 which is about 1v higher than battery voltage albeit about a volt less than it should be? Engine is a 2003 mercruiser mx6.2L serial #0M30xxxxxx