Charging from outboard - not working? How to tell?

[Rick Macdonald]

I bought a multimeter a few months ago. I pull started my Honda 9.9a and with the O.B. cables not connected to the battery, there is no voltage across the cables wile the engine is idling. With the meter set with the same way, I read 12.74 directly on the battery (in case somebody asks if the meter actually works).I checked the 15A fuse under the cover, and it's OK. The electric start works OK.Shouldn't I see 12V across the cables? What could be wrong? I've used the engine for 3 seasons. I guess I have no way of knowing if the charging has ever worked....RickM...

 

[Henry Scurlock]

Sounds like the rectifier/regulator

You should be able to measure the INPUT to the regulator. Should be AC voltage.check page 77 of attached link for schematic

 

[Rick Macdonald]

Where on the engine?

Thanks. I see it on the diagram. Does it show in the picture on page 63? Is this something that I can replace myself or does it need to go into the shop?...RickM...

 

[Henry Scurlock]

Sorry, can't help much with the physical...

location of the part. I had it replaced on my 5HP a few years ago. Pretty pricey if I recall, but then I'm a klutz and would probably have cost myself more trying to do it myself.You should be able to track the wiring from the fuse back to the rectifier. If I recall correctly, the wiring is pretty simple in there.

 

[Paul Akers]

Take the reading...

...when the engine is revved. The alternator won't charge at low rpm's.

 

[Rick Macdonald]

Ah, revved!

Thanks, I wouldn't have thought of this. The boat is 90 minutes away so I won't get to test it again until the weekend. I'm hoping to launch for the season, so if it isn't charging it will have to wait another season.If the charging wasn't working, would the battery last and run the electric start for 4 months? I can't guess how many starts that is - maybe 40 to 100? The battery didn't die last season or the two previous. I don't use any other power besides depth/knot meter....RickM...

 

[Rick Macdonald]

Tried revving, but still no charge

Oh well, next winter I'll have to take it in for service. Assuming that it has never worked in the three years that I've had the boat, I guess I won't miss it this summer....RickM...

 

[Ron M]

Solar

Rick - You might consider helping the battery along with a solar charger. Otherwise, use your multimeter to measure batt voltage thoughout the season. There are tables to be found that relate voltage to percent of battery life left.Ron Mehringerh26 Hydro-Therapy

 

[MABell]

Running unconnected

I asked the mechanic at the Yanmar dealer about running the motor without the wires connected (I was worried about over-charging the batteries). He indicated you can destroy the charger when running the motor with wires not connected to the batteries. In other words, the current needs somewhere to flow. On an inboard, it can blow the dioides in the alternator. Don't know what it does exactly to an outboart. Sort of a catch 22 to determine if there is current being produced. After having it looked at (fixed), measure the battery voltage before and after running the motor for a period of time.

 

[Rick Macdonald]

Good news, maybe

MABell's post was bad news to me since I've been running unconnected to the battery. :-( I phoned a couple shops in my city but got no free information, so I called the shop in Vancouver (Carter Honda) where the O/B was serviced when I bought the boat three years ago.They say the charging system on the Honda 9.9 automatically shuts if it's not connected to a battery or if the cables are shorted. I was told the proper way to measure is to connect it to the battery, and running at half throttle you should measure 15 to 16 volts.So, I might be OK after all! I'll be checking this out over the weekend and will report my findings....RickM...

 

[Tim Peoples]

Check with the battery connected

You can check if it is charging with the battery connected. Take a reading with the multimeter with the engine off. Then start the engine and give it some RPM's. Re check the reading. If it is charging then the reading will be higher than before you started the engine.

 

[crazy dave]

did you drop the chord in the water?

If you have dropped the cable into the water or the two touched, then the first is to check the fuse inside the engine cowling. If it is not that, then you may have screwed up the alternator and if so, best you take to a mechanic.

 

[Rick Macdonald]

Yes! It does work!

So, the Honda shop in Vancouver was right on the money. With the cables hooked to the battey, the voltage goes up as the engine is revved. I couldn't get it to the 15-16V range as they said though. Even at full throttle I got about 14.8 volts. Well, at least it not broken after all....RickM...