Yamaha F350s not charging batteries

[Rezoned1]

Good afternoon,

I am hoping to gain some insight on an issue we are having with the twin F350 engines on our 2008 Contender 33T.

Two weekends ago we left the dock on Friday afternoon for a weekend-long fishing tournament. Our 3 batteries were fully charged and the boat was running great. We ran at 4600 RPM for a couple hours and then slowed down to just over idle once it got dark. We continued on our course for roughly 6 more hours by only using one engine, alternating the engines every couple of hours. during this time we were running radar, GPS, bottom machine, 2 livewell pumps and, of course, the stereo. We also had spreader lights on occasionally.

Once tournament hours started, we fished for about an hour and then started getting low voltage alarms from the gauges and electronics. A few minutes later we lost all power on the boat.

We had a jump box on board and used it to jump the engines, but they died almost immediately after engaging the throttle. We then used the jump box to start one of the engines, and it was able to idle in gear for 10 minutes before losing power. We checked all connections and grounds (that we knew of). Once we determined that the issue was more than something simple, we called Tow Boat US on the satellite phone and had them bring us 4 heavy duty marine batteries. Once we received the batteries, we hooked one up to each of the engines, cranked them up and the engines ran like a top. We started heading in at normal cruising speed and could watch the battery voltage slowly drop. Eventually (several hours), the port battery was too low for the engine to run and the motor shut off. At that point we installed the last two batteries and were able to make it all the way back to the marina without losing power again, but the battery voltage had dropped substantially.

One of our good friends is a Yamaha mechanic and he was willing to go down to the boat and hook up the diagnostic computer with hopes of helping us troubleshoot the issue. These are the codes that were picked up:

Port Engine:

Engine R/C Communication Code 156

Engine R/C Communication Code 157

ETV Code 144

Pulser Coil Code 13

Battery Voltage Code 19


Starboard Engine

Pulser Coil Code 13

He also said that he was able to confirm that there was no power coming out of the engines, headed to the batteries (I am not sure which points he checked).

I am hoping that some of you experienced Yamaha techs would be willing to weigh in on this situation. The boat is kept on a lift, and we do not have a trailer, so we would like to do as much homework as possible before developing a plan to have the situation addressed.

Thanks in advance for any advice given!

-Dan
Tallahassee, FL

[rodbolt17]

its a fairly basic AC to DC regulated system.
check the lighting coils.
if the lighting coil resistance and outputs are in range then check the regulator/rectifier.
that's about all there is in that charging system.

are the battery isolators wired up on the motors or are the connections just drifting around in the lower cowl?

my guess is your going to need a tech that has certificates for electrical and 4 stroke systems at a minimum.

if the tech does not have them find a real tech.

if you lose battery voltage that ECU is going to toss all sorts of codes as almost EVERYTHING on that motor uses 12v.
much below about 10V your going to lose ign,fuel pumps and the main relay.
much below about 9V and you lose the ECU in both the engine and the helm.

[boscoe99]

Extremely rare for both electrical outputs of two separate motors to fail at the exact same time.

A conventional configuration arrangement would have one battery supporting one motor, a second battery supporting the second motor and a third battery supplying power to everything else in the boat. Each motor and its respective battery would be isolated from each other and also from the third battery such that either battery could fail, or either motor could fail, without adversely affecting anything else. Your motors also each have a second electrical output that may or may not be in use. There are also aftermarket devices that can be used to charge different or multiple batteries from each motor. Known as a combiner/voltage sensitive relay (VSR)/automatic charge relay (ACR), etc. Hard to guess how your boat is configured. Do you know?

First to do (after checking all fuses of course) would be to isolate the two motors from each other and from the third battery. Make sure each battery is fully charged. You should see approximately 12.7 volts on each. Start motor number one. The voltage measured at the battery should begin to rise and over the course of a minute or so one would expect the voltage to rise to nominally 14.5 volts with the motor running at a fast idle. Start number two. The same thing should occur. This will indicate each motor is doing its job of creating electricity and providing it to recharge each battery. If this does not happen then you would test further to determine the source of the problem. Magnets inside the flywheel wiz by some coils and create electricity. That electricity is fed to a device that converts it, regulates its voltage, and supplies it to the battery. Either of these components could be the source of the problem. See the diagram below. It is a relatively simple system using mostly 100 year old technology. Any Yam or other brand outboard mechanic should be able to test the system to determine the source of the fault.

Find and fix the lack of voltage problem first. As rodnut notes, lack of voltage will cause all sorts of spurious codes and strange running problems.

[rodbolt17]

the above diagram appears to be for an F225 3.3L.
but the concept is the same for the F350.
the F350 uses a single delta wound charge coil that has 3 charging legs(green wires).
the rectifier assy has 2 red outputs and 1 ground wire.
most all Yamaha V6 since about 1990,inline 4 F150 and up and all V8 have a built in battery isolator circuit. no need for VSR's and other devices simply use what Yamaha provided.
kinda like turn signals on your car.
you paid for them why not use them?

[boscoe99]

Diagram is from the F350 service manual. LIT-18616-03-08.

Two delta wound lighting coils. Three output legs per coil.

First year F200/225 did not have an isolator lead. Later years did.

The mysterious part is why did so many carburetted and EFI two strokes have knock sensors but then along comes the HPDI and no knock sensor? Why leave it out?

[fairdeal]

Two delta wound lighting coils. Three output legs per coil.

First year F200/225 did not have an isolator lead.

That puzzles me.
Here's - according to someone selling it on eBay - the output connector on a 69J-81960-01-00 rectifier





Two 3-leg leads in. Why two leads out - if they are not "isolated" ?

[boscoe99]

That puzzles me.
Here's - according to someone selling it on eBay - the output connector on a 69J-81960-01-00 rectifier




Two 3-leg leads in. Why two leads out - if they are not "isolated" ?

Don't confuse two output leads, one from each lighting coil, with the "isolator" leads.

Since you are from Missouri (the showme state) see the diagrams below:

[boscoe99]

More for the fairdeal enquiring mind:

[fairdeal]

ok - now you're reminding me that its two years since I first saw that diagram,
and I still refuse to make the mental effort to work through exactly what all those diodes are doing...

but since Yamaha calls that device "Fuel pump driver and isolator" - it is suspicious..

So then here's my next "wonder", not having access to any other Yamaha electrical diagrams -

do all these motors Rodbolt speaks of, "most all Yamaha V6 since about 1990,inline 4 F150 and up and all V8"

do they all have, in addition to a "rectifier", a separate solid-state "isolator" device ?

[fairdeal]

More for the fairdeal enquiring mind:

nice. You certainly have an awesome library!

[boscoe99]

ok - now you're reminding me that its two years since I first saw that diagram,
and I still refuse to make the mental effort to work through exactly what all those diodes are doing...

but since Yamaha calls that device "Fuel pump driver and isolator" - it is suspicious..

So then here's my next "wonder", not having access to any other Yamaha electrical diagrams -

do all these motors Rodbolt speaks of, "most all Yamaha V6 since about 1990,inline 4 F150 and up and all V8"

do they all have, in addition to a "rectifier", a separate solid-state "isolator" device ?

I think the fuel pump driver and isolator comment is an error. There are two circled number 3's in the later SM. Both have the same name but completely different functionality. One should have been the fuel pump driver and the other should have been the R/R isolator IMO.

In the parts book there does not appear to be a separate isolator component that is part of the electrical output system. The parts book shows a "drive unit" but I believe that is referring to the fuel pump driver.

The isolator function is usually embedded within the rectifier/regulator. Some R/R's have it and some don't.

[fairdeal]

I think the fuel pump driver and isolator comment is an error.

Well, not for the F225TXRD (the only model, of course, of which I can speak with authority).

Its quite a striking gizmo to see - it really does have 5 separate leads!

The isolator function is usually embedded within the rectifier/regulator. Some R/R's have it and some don't.

Got it. Thanks again.

[boscoe99]

Well, not for the F225TXRD (the only model, of course, of which I can speak with authority).

Its quite a striking gizmo to see - it really does have 5 separate leads!



Got it. Thanks again.

I see the five leads from the drive assembly but am not convinced it is part of the regulator/rectifier. This is where you come in.

Can you check your R/R and verify (or advise otherwise) that it has at least two inputs (from the stator), two outputs (one of which may not be in use if you don't use the isolator lead) and a ground lead?

Check your drive assembly and I suspect that you will find it is not part of the electrical output system. Can you document the wire colours that are being used in the five connectors?

[boscoe99]

Upon further review, it might just be that on the F225D Yamaha used a R/R without an internal isolator and combined it with the updated fuel pump driver.

What in the hell where they thinking? This is the only model that I have come across that does it this way. Seems that when they discovered the failed to include an isolator lead in the first version of the F225A they cobbed together a bastardized way of offering it.

Pity the poor mechanic that has to try and troubleshoot the bastard system.