Mercruiser 4.3 alpha 1.

[Foster86]

I had been riding in my boat approximately 6 hours stopping time to time. The radio played some but nothing else. The last ride lasted 30-45 minutes. I noticed my tach not working after jumping a good size wake but to boat ran fine (2012 Tahoe Q 5). When getting to the dock I allowed my boat to run idle until I came back to get it for loading on to the trailer. As soon as I pulled away from the dock and began to trim the motor up it died. It wouldn't restart as the battery was dead. I had just put a
new deep cycle battery in as last week
the original battery died (1 year old). When running down the lake I cut off the master switch. Does that need to be on to charge the battery? Or considering I just had to replace the one year old original & now have a dead new one, should I consider an alternator problem? Can it be something else?

 

[spdracr39]

Re: Mercruiser 4.3 alpha 1.

Yes the master switch must be on to charge the battery however if it is wired correctly if the master switch is off the motor should not run. It sounds more like to me you have bad connections. Are you sure the battery is dead or would it just not crank? Get a volt meter and check the voltage at the battery. It should be between 12 and 13 volts. Start the boat on the water or on the muffs and check it again. With it charging it should be between 13 and 14 volts. If your voltages are good start checking connections. The connections at the battery should be removed and cleaned. When you put them back on throw away the wing nuts and get regular nuts you can use a wrench to tighten. Check the wires on the back of that master switch next. It is possible to get a crappy battery but I don't think that's the issue.

 

[sptjet90Reflexx]

Re: Mercruiser 4.3 alpha 1.

Don't let voltage fool you. Just cause you have volts does not mean it will crank anything. You need amps. (the current) Only way to properly test a battery is using a load tester.