2002 200HP HPDI Won't Charge Battery

[Peppy123]

Took my boat out for some inshore fishing a couple of months ago. Run out to fishing spout was about 45 minutes at WOT. No issues. Ran around to several spots during the day. No issues. Starting running back in WOT, and about halfway back, engine started lugging, and eventually slowed till boat lost plane. Brought to neutral, then tried to get going again, but wouldn't allow me past half throttle. Looked at guages and noticed voltmeter pegged low. Was able to get boat up on plane at about half throttle (3200 rpms) and make it in. Checked battery when I got home, and dead. Tried to charge, wouldn't take it. Bought new battery, went out the other day, and halfway through the day, battery dead again. Used jumper cables off of *****ing motor batteries to crank and get back in.

Is this a simple fix, and something easy to check with a meter? Should I check for other contributing causes?

[amahaork]

not sure about yours, but I loosing charge for day fishing and on a way back switching to second battery. It is a simple procedure in Yamaha service manual how to check charger coils for continuity and resistance. but I change all cable ends, same cables - new ends and some soldering torch and also changed master switch, as contacts inside may be corroded and give big amperage consumption. same for auxiliary cables to electronics. Try it.

[rodbolt17]

its a fairly simple system.
you have 3 lighting coils.
1 rotor(flywheel).
and a regulator/rectifier.
that's about it.

[Peppy123]

its a fairly simple system.
you have 3 lighting coils.
1 rotor(flywheel).
and a regulator/rectifier.
that's about it.

Thanks for the responses. Rodbolt, would it charge at all if any of the coils were functioning, or is it more likely to be the regulator rectifier? Are the three coils in series? While running I put my meter on the battery terminals and saw no voltage increase when I revved the engine, so I am assuming I am getting nothing from the charging system.

[rodbolt17]

the rotor rarely fails, its not the problem.
can the stator fail? yep but its a simple thest.
its a delta wound 3 phase simple system.
if the coil resistance is correct and the coil outputs are correct then test the regulator output.
its a stupidly simple AC altenator.
the altenator in your car works exactly the same way.
rotate a magnent past a coil and you get an AC voltage output.
feed that output to a rectifier and you get a DC output from the rectifier.
there are 3 green wires coming out of the lighting coil.
a b and c
test resistance a-b, b-c and c-a then test a b and c for shorts to ground.
if it passes its most likely good.

[Peppy123]

Ok. Had some time today to perform some checks. No shorts to ground in the stator. Performed measurements on rectifier/regulator with my meter on diode check setting. Connected first the neg on meter to each of the green wires into rectifier, then the positive to the two red wires out of the rectifier. There were differences in the readings (1541/1212/1546)millivolts and (1868/1623/1870)mv. Switched the positive and negative on the meter and got (486/489/478)mv and (487/487/486)mv.

Am I correct that the lower readings in the first numbers (1212 and 1623) indicates that the rectifier is bad?

Like you said, it's a simple system, without many parts to fail.

[rodbolt17]

that's about right.
its a diode.
takes about 475 MV to forward bias it.
test the stator lead resistance A-B,B-C and C-a.
should all read close to 0 ohms.

[Peppy123]

Yes, I tested the coil leads. All legs 0.3 ohms.
Thanks for the help. Ordered the rectifier.

[madharchod]

the reason why this happens is either you forget to connect the wires to the battery or you have loose connection at the terminal thus it burns the rectifier

[Peppy123]

Interesting. Ok, are you talking about the main battery cables leading to the engine? I can understand them getting loose, but not sure about forgetting to connect them. Just making sure you aren't talking about another wire.

[99yam40]

if you read most of Mad's post they do not say much, so take them as you care to