F90c electrical issue?

[Jer bear]

Hi, I have an 04 F90C that I have had for 4 years problem free. Last week when prepping the boat for the season I noticed the older, (non-original) battery was dead. I had kept it on a battery tender through winter as usual and had started the boat the day I put it back in, next day it was dead. No biggie, I thought. Went and bought a marine battery with same cranking amps as old one, replaced it and everything seamed fine. I also hooked up a fish finder (previous owner had one on the boat before and left the wires) so I just tied into that positive and negative that he had used. Everything seemed to work fine. Friday I headed out on the lake, only used the fish finder for a few minutes then shut it off. When heading back to shore I noticed the trim wasn't working, shut the boat off to inspect and had no power to start engine or do anything for that matter. When back home I recharged the battery and did some inspecting and found the 30 amp fuse had blown, replaced it and tried it, fired up the engine and it was showing a little less than 12 volts on the gauge while running, within a minute the fuse heated up and as soon as I tried an accessory light it blew the fuse again. I also noticed a little smoke coming out from under the flywheel. I would appreciate any help with this situation, I'm not an expert when it comes to electronics so before I mess around with it anymore, I wanted to ask here. Thanks in advance for any info.

[bajakeith]

Dont Touch That Dial !!

I suggest you find someone that really knows electrical !! oop's !! and outboard systems,,nothing like a car.. having billy bob at the marina boat shop can get you in a deep _ _ _ _ Fast !! ask around ..ask the reel boaters in your area for info on who has the Tool's,"Touch",,,know how and really cares about his work and reputation...this time of year he should be real busy..so start looking today and be prepared to get on a waiting list...btw,,,I can assure you that its not the motor's fault,,,owner operater bad electrical is almost always the issue...And don't let a audio store install a sound system in a boat....Grrr !!

[greasyshaft]

Your house circuit should not be connected to power via the outboard, you will need to run separate wiring from the battery for you house supply.

Pop the cowling and have a look at the rectifier/regulator lower front of the power-head (underneath intake silencer) sometimes they burn up.
Are all battery connections tight?

[BoatMon345]

I suggest you find someone that really knows electrical !! oop's !! and outboard systems,,nothing like a car.. having billy bob at the marina boat shop can get you in a deep _ _ _ _ Fast !! ask around ..ask the reel boaters in your area for info on who has the Tool's,"Touch",,,know how and really cares about his work and reputation...this time of year he should be real busy..so start looking today and be prepared to get on a waiting list...btw,,,I can assure you that its not the motor's fault,,,owner operater bad electrical is almost always the issue...And don't let a audio store install a sound system in a boat....Grrr !!

Stop intimidating people, "bajakeith" aka "Famous Flamer", from attempting to fix their problems themselves. You have a track record of being a know-it-all, and by what you have stated, you have contributed nothing to the post.

Good job Jer Bear on your description. I am sure there will be others who will chime in with experience who are willing to help. Don't give up on fixing your issue. I didn't give up on my issue.
From the way you write, you definitely sound smart enough to get to the bottom of this problem.

[rodbolt17]

I agree with Baja on this one.
its a fairly simple charging system.
has a rotor aka flywheel.
a stator with lighting coils that feed 3 phase A/C voltage to a rectifier regulator.

however its rather expensive to repair once things start melting.

typically if you light up the rectifier it melts the harness and ECU.

I have never been a fan of the air cooled rectifier assy on the inline EFI motors.

so without a bit of working knowledge and the correct test harness's and a working knowledge of using a volt meter you may dive in over your head.

[boscoe99]

How convenient to mount the rectifier/regulator right under the CDI. The perfect spot to cause the most expensive damage. Yamaha gets to sell two components for the failure of just one.

Let's not mount it above the CDI so that it will be closer to the rotor, where it might get a bit more air movement, with less wiring being needed from the rotor to the stator. And, when it lights up it won't be as prone to damaging the CDI.

Think engineers, think.

[TownsendsFJR1300]

Besides the new engine charging issues, it sounds like the rest of the boats electrics (lights stereo, depth finder, radio, etc) are tied direct to the engine somehow.

As noted, you should have at least one FUSED, separate + & - line for the hulls lights, bilge pump, etc (from the hull maker/factory).

I installed a second line to the battery (fused right there at the battery) that goes up into the center console. From there, it ties into a power distribution block. ALL my accessories come off of that and are fused from there. Anything that pops a fuse is stopped right there. I the main line pops the fuse, it doesn't affect the running lights or the engine..

Your's is apparently all tied together incorrectly. IMO, consider getting the hull checked, or re-wired to separate the systems...

BTW, that accessory light you first mentioned, sounds like it has a BAD "dead short" to pop the engines main fuse.

[bajakeith]

To: boatmom345

Hey ,FOOL please tell us when your repair (used loosely) on you motor BLOWS UP !! I learned years ago not to argue..as that would make two (2) fools...LOL "famous flamer" ??? is that a good thing ?? Well,,Thanks then !! Never heard that compliment before and I don't really don't need to be liked by you.... waiting for UPS with my parts.......

[boscoe99]

OK boys. Time for some of you to move on over to the hull truth. They love piss, moan and argue over there.

[TownsendsFJR1300]

OK boys. Time for some of you to move on over to the hull truth. They love piss, moan and argue over there.

Just a little common RESPECT would likely cover it. Treat someone the way YOU would like to be treated works for me...

If you don't anything good or helpful to say, don't say it...Easy peezy...

[Jer bear]

Thanks for the suggestions guys, I traced all the wires for shorts as much as I was comfortable doing, and since I don't have any meters or patience for electrical problems I brought it to a marine mechanic. Hopefully it's nothing too serious. Thanks again

[TownsendsFJR1300]

Thanks for the suggestions guys, I traced all the wires for shorts as much as I was comfortable doing, and since I don't have any meters or patience for electrical problems I brought it to a marine mechanic. Hopefully it's nothing too serious. Thanks again

Please post back what the issue / fix was..

[Jer bear]

Mechanic found a burnt up rectifier/regulator, hopefully I can find one within driving distance, or get one overnighted. I'll let you know if that fixes the issue when it's back together.

[greasyshaft]

Fire!! I love it

[TownsendsFJR1300]

Mechanic found a burnt up rectifier/regulator, hopefully I can find one within driving distance, or get one overnighted. I'll let you know if that fixes the issue when it's back together.

Thanks for the update.

Do you know if the boats wired up with accessories direct to engine or separate lines? (referred to in post #7).

You don't want a separate electrical issue elsewhere on the boat affecting the engine...(referred to in your first post with the accessories and popping of fuses immediately)