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BF225 charging system alarm

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SureThing!

New member
I just found this site and have searched for all the info I could find but could not find out exactly how the charging system works.
I have a 2006 BF225 that the battery light illuminated and gives off the consistent long beep audible alarm once it is started. I verified the altenator is not charging by turning off the battery switch while the motor is running. The motor stops immediately. I measured battery power at battery and it was 12.7vdc. I measured the output / battery terminal on alternator and case and I have 12.7 vdc. I also tried to measure voltage drop between battery positive terminal and output wire on alternator as well as between negative post on battery and case of motor. Both were 0 vdc. This confirms my wiring between battery and alternator are solid/ good connections.
I then pulled the 4 pin plug to alternator with the motor off I measured each wire in the plug to ground and then started motor and did it again.
Measured 4 input wires to alternator.
Ignition off:
White/ black stripe —12.7vdc
White/ blue stripe— 0vdc
White/ green stripe— 0 vdc
Yellow/ black stripe— 0 vdc

Ignition on:
White/ black stripe —12.2vdc
White/ blue stripe— 12.2vdc
White/ green stripe— 5 vdc
Yellow/ black stripe— 12.2 vdc
I then thought it was a bad alternator, so I pulled the alternator and took it to a electrical shop that rebuilds motors and had them bench test it.
I was told the alternator put out full current and was good. They told me the alternator has an external voltage rectifier.
I found this article on Honda’s dual output charging system used on honda cars.


The way I understand it there is an ELD electrical load detector that appears to be a shunt in the circuit. Located in the fuse box on cars that regulates the output voltage on the alternator.
Basically when there is a large load on the charging system it pulls the 5 vdc signal down to 1-2vdc and the alternator puts out full output of 14.7vdc at 80 amps.
Does anybody know where this ELD is on the BF225?
Or
If this is not the way the BF225 charging system works, how does the sensing circuit work so I can troubleshoot that portion of my charging system. Any help would be greatly appreciated. I’m on the beach until I get this resolved. I would take it a shop and put it on a laptop if that was an option, but the soonest someone can look at it is mid September and the Salmon season is over where I live in western washington.
 
When you turn on the ignition, do all four indicator lights flash briefly and you get two short beeps?

When the engine is running, are all of your instruments working correctly? The reason I ask is that there is a 7.5-amp fuse in the wiring harness to the instrument panel.

Did you test the big 150 amp alternator fuse?

With key on, but engine not running, Is your tilt/trim working? With engine running, is your tilt/trim working and is it noticeably faster than with the engine off? If so, you may not be getting enough amperage. You should be measuring the amps coming off of the alternator and regulator. Your voltage could appear OK, but you may not be getting the amps you need.

I know of no ELD on this engine, unless it is built into the regulator. However, I'm not an expert on Honda electrical, so maybe someone else has more information.
 
Hi,

Maybe a dumb question but is the alt drive belt tight and rotating the pulley and rotor shaft properly?

Like chawk_man, I'm no Honda electrical expert either.

But, looking at the wiring diagram in the manual chawk_man has posted on this site in the past, I see no external voltage regulator or ELD.

Page 6-5 shows an IC regulator bolted directly inside the alternator.

The wiring diagram indicates ECM supplying field current flow via w/g wire where you measured 5 volts koer

The manual cautions against disconnecting the battery while the engine is running. Page 6-1

This appears to be a.more "cconventional" charging system than the one you referenced but I have no knowledge of the charging strategy.

Could it be that the electrical shop gave you some bad advice?

Sorry you're having troubles.
 
Thank you Chawk- man and jgmo. You made me go back from the beginning and spend more time with the manual. I had skipped over the ecm, troubleshooting and alternator chapters. It appears my electric shop gave me some bad info.
According to the manual I verified my light circuit was working properly. I used the charging circuit troubleshooting flow chart. In the end it said to replace the alternator. I removed the alternator and tore it down. I’m not sure how the alternator was even working. The brushes were completely gone and the slip rings were destroyed. I’m going to order a new alternator and belt and with fingers crossed I will be back on the water again.
 
Good news! Glad you figured it out. You seem to be headed toward a PROPER repair.

Too bad it has to happen this way but at least you now know where NOT to visit for electrical repairs.

Your plan sounds like a good one and I hope we hear back from you about the successful outcome.

WRENCH (and rock) ON! ;~)
 
SURETHING,
Just curious, how many hours on your 2006?
Wondering what I can expect to get out of my alternator, also a 2006 225, 700+ hours.
 
Thank you Chawk.
I envy you all those hours, short season for us up here and work gets in the way. Looking forward to retirement so I can get more time on the water.
 
Roger that. A good hunk of those hours were in the Gulf Stream. I used to trailer the C-Hawk down to Hatteras from December to mid-April to fish for tuna and mahi. Can't do that any longer. So, I'm confined to the lower Potomac and middle Chesapeake Bay.

I haven't had the old girl out much this year. In early June, I pulled for a 200-hour maintenance and found that the main drive shaft needed to be replaced along with some bearings. Tested it over the weekend and now it must go back to the shop because not working right. Plus waiting for parts after finding a few other issues. And, I had to have trailer tongue replaced which took five weeks to get a replacement. It's been a lousy summer, boating/fishing wise. Hoping to get back on the water for the Spanish mackerel run and then fall rockfish season.
 
VinalHaven,
I have around 700 hrs on my 2006 BF225. My alternator failure is premature due to spraying my engine with corosionX in the fall when I lay up my boat for the winter. I must have been a bit over zealous with the stuff and it dripped down into my brushes and acted as a grinding compound. It wiped out the brushes and the slip rings. That said it didn’t rust/oxidize. The alternator looks brand new. —>Lesson learned
 
It's a good idea to spray down steel parts to rust inhibitor, but very carefully, as you now know well. Personally, I prefer WD-40. The other place that you need to be very careful about is the area under the electrical cover on the front of the engine.
 
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