Charging question F25T

[MadMacX]

Hi Guys,

I'm new to this boat/outboard thing, and have a couple of questions. Hope someone can point me in the right direction.

I have a 1998 Yamaha F25T LRW on my sailboat and have both a starter battery and a house battery set. I want to install a isolator so I can charge the batteries while under power, but not discharge the starter battery, when on the hook. My problem is my Yamaha charges through the battery cables (I think), so I can't hook up the isolator to prevent drawing down my starter battery. Would using a switch make more sense? Any ideas?

Also, I have looked everywhere but I can not find what the amp output on my Yamaha is, anyone know? What does my Yamaha use to produce DC voltage?

Any assistance will be sincerely appreciated.

Pat

[boats.net]

It has a 15 amp alternator at wide open throttle. If you install a battery isolator it will charge 2 battery's separately.

[MadMacX]

Thank you for the quick reply.

Can you tell me where I find the wire from the alternator that has to go to the isolator? Or, do I just attach a wire from the starter battery to the alternator post on the isolator? I'm sorry if the questions seem dumb, but I don't have a service manual for my motor and have not been able to find one.

Thanks,
Pat

[boats.net]

Not all isolators are wired the same, follow directions that come with isolator.

[MadMacX]

Not all isolators are wired the same, follow directions that come with isolator.

The isolator states that you are to attach the ALTERNATOR WIRE(meaning the wire from the Yamaha alternator) to the center terminal of the isolator. All I am asking is where is the alternator wire located on the Yamaha, and what color am I supposed to be looking for? If there is no alternator wire to attach to the isolator, I assume that I can attach a wire directly to the positive terminal of the starter battery, as the alternator is charging the starter battery. Make sense????

Regards,
Pat

[boats.net]

The alternator output lead(12 volts dc) is the red wire coming from rectifier to starter solenoid.

[MadMacX]

The alternator output lead(12 volts dc) is the red wire coming from rectifier to starter solenoid.

Thank you very much, I really appreciate your help! I owe you a beer.

Pat