BF130 Warning Buzzer - Diode Splitter

OK,

Had an issue with the Alternator and while waiting for a replacement added a diode splitter so that the engine charges 2 batteries.

Alternator was definately FUBAR but the motor would run and I got a ACG fault light and a warning beep (oil pressure light green and on and overheat off).

So while waiting for the new unit, replaced the main wires to the Starter and Ground, then cut the alternator output wire off the solenoid and spliced to a third heavy duty wire (after the 90A fuse) which goes to the diode splitter and then to the main and 'house' batteries. All terminals crimped and soldered.

Now the new alternator is fitted, still have the same fault (or the same symptom), though voltmeter shows a 14.7v output at the alternator terminal, same at the Diode block input and the house +ve is 14.6 but the main is only showing 13.2.

As the terminal on the starter is to the main battery, is the on board diagnostics registering the 13.2 and expecting it to be higher with a working alternator?

Should one of the smaller white wires on the solenoid terminal now go direct to the alternator output to allow the on-board diagnostics to 'see' a working alternator.

Or could it be that there is still a fault which was simultaneous to (or resulted from) the alternator going bad?

I get the feeling that I'm missing something obvious, as I've done this sort of thing before on Diesels with no issues. Damn those Little Black Boxes...

Not sure I would remove other leads, they perform several functions.

Two things to check. Check the 10 amp fuse, it may be blown, thus the alternator has no sensing circuit.

If all that is ok, take the diode arrangement back out of the circuit and see what you have. There may be something else wrong.

Get it working without alarms before more modifications.

The Honda recommended way is, of course not to cut wires or modify. They recommend a battery switch arrangement like on this page. http://marine.honda.com/outboards/accessories/battery-management It allows total separation of the batteries when the motor is not running unless you throw a switch to jump start the motor (in case one of the batteries goes dead). With the voltage sensing relay, the starting battery gets charged, then when fully charged, the switch connects the two batteries in parallel for charging. When the motor stops, the relay switches off and the batteries are again separated.

These switches etc. are made by BEP and are not cheap, but they are pretty slick. You can get by with just a voltage sensing relay (about $100) and no battery switches, although that removes a lot of flexibility.

Mike

Thanks,

I'll look into the VSR, and the 10A fuse is certainly a good place to start. The wiring had already been hacked about a bit before I got it, and it's been a saltwater unit all it's life, so I suspect something else will be misbehaving too. At least it's not an intermittent fault.

I'm not exactly following what you are doing with the splitter. BUT, if you are reading the voltage off the ECM, it IS stepped down to about 13.4 volts. On my setup, I added an analog voltmeter at the cranking battery. When motor is running, it reads 14.6 volts on average. However, my Honda Digital Gauge reads 13.4 volts. That reading comes off the ECM. I checked it with a very accurate multimeter, and it confirmed the 13.4 volts. Asked my dealer about why the difference, and he did not have a good axplanation, but confirmed that was the correct reading.

Thanks for the input so far,

I had a feeling this was going to be a real PITA to fix, so far proving to be the case.

Diode Splitter and second battery disconnected - same fault.
10A fuse (and 2x 30A and also 90A fuse) all checked with digital multimeter. All A-OK.

Swapped out the ECM with another BF130 - same fault.

Alternator is charging - put a digital meter on it and as before 14.6v on the alternator terminal but the buzzer is going beep beep beep and it's REALLY getting on my nerves (I CAN fix that with a 2lb hammer but I suspect that is not a valid honda repair technique ). The ACG fault light is also on.

At the moment I'm thinking there is either an internal fault with the alternator or a wiring loom problem between the alternator preventing the ECM from recieving the signal that the alternator is working even though it is producing charge.

Annoyingly the other motor also has a duff Alternator so I can't swap that out to check.

There are three wires onto the plug at the back of the alternator (Little square green plug with 4 pins but only 3 are connected)
Yellow (Black Tracer)
White (Blue Tracer)
White (Black Tracer)
(If I Remember right...)

The socket is labelled with L, IG, S but the wiring diagram I have from the downloaded manual

http://marine.honda.com/Owners/Manuals/models/BF130

is pretty much grainy and unreadable.

I understand the alternator has the voltage Reg circuit onboard.

Anyone know what the voltage readings should be from those pins on the socket - I'm guessing I need to input 12v to one of those terminals to energise the alternator.

Thanks in advance

Opps forgot to tell you to check another thing. Check the 90 amp fuse also. You tested 14.6v at the alternator, but how about at the battery? The alternator may be putting out voltage, but no current.

If you happened to connect the battery backwards even for an instant, the fuse will blow.

Also, make sure you have a good battery.

I will check on the other voltages,,,do not know them off the top of my head.

Mike

-The output terminal should be 12v (battery voltage) when the motor is not running (thru the 90 amp fuse). Should be 14.5v or so when motor is running.
-The Yellow/blk lead should be 12v when the key switch is turned to on. From the main relay.
-The White/blue is the one that lights the light and tells the ECM to sound the audible alarm. If the indicator light is on, the voltage is 0. If the indicator light is off, the voltage is battery voltage.
-The White/black lead should have battery voltage all the time (10 amp fuse)

Hope that helps.

Mike

Awesome, That was just what I needed to find out

-The output terminal should be 12v (battery voltage) when the motor is not running (thru the 90 amp fuse). Should be 14.5v or so when motor is running.
Yes, indeed it is.

Will be checking the other leads tomorrow, though my colleage checked the White/Black and is as you said.

From the symptoms I suspect a broken Wh/Blu wire but will establish that the alternator is infact outputting 12v to it first.

Thanks again

Andy

Maybe a grounded wh/blu?


Mike

Thank you Mike,

The White/Blue voltages were the key.

Sadly it is a dead voltage regulator which is not available on Island but I have a friend coming down in a week so I get one then.

I popped the green plug and also the big plug on the ECM and tested the wire for both continuity and also for grounding = passed.

I re-installed both plugs and was able to get a needle probe into the connector alongside the seal - 0v with engine running and system charging.

As a final sanity check, applied 12v to the needle probe and the light went off and the buzzer went quiet (Ahhh Bliss).

Do these things fail regularly (i.e. for a hundred bucks, should I keep one as a spare, especially as the local dealer doesn't carry much of anything BF130?)

Thanks again,

Andy

Glad you found the solution. I have not seen these to have much trouble, although the 130's have been around since 1999. I would assume that things will start failing.

Mike