Honda 130 efi alternator trouble

My honda 130 efi has the alternator light comming on and the buzzer. When the motor is running And I unplug the alternator, the alarm and light go off. Before I replace the alternator I would like to test it. Can somebody please tell me how to test it. And is there anything else I should be looking at? I have a voltmeter and ohm meter. Also, if I find that it is bad should I replace it or take it to some kind of repair shop? Any information will be appreciated. Thanks.

If you don't have access to a hand held load tester and don't want to take it to a repair shop, you might try pulling the alternator and having your local auto parts store test it for you (usually free). You should also check the cables on the alternator and your battery for corrosion (usually under the terminal boots).

If it tests bad, and you want to install the new one yourself, the parts store may be able to cross reference something they stock or you could always order it from the internet and install it yourself. It's usually a good idea to replace the belt at the same time. Course, you could always take it to a shop and let them do the work.

Hope this helps,
Jayson

It is interesting that disconnecting the connector eliminates the buzzer, but as I think of it, the regulator is connected directly to the light through that connector. Usually, when you disconnect a connector, an alarm will sound.

Anyway, one easy check would be for you to connect your voltmeter to the starting battery when the engine is not running. See what the voltage is then watch what happens to the voltage when you start your engine. If the alternator is working, the voltage will increase to 13v to 14v volts or so.

If the voltage drops or just stays the same, the alternator is probably not charging.

Before you pull it though, check the 90 amp fuse (#5) http://www.boats.net/parts/search/Honda/Outboard Engine/2002/BF130A2 LA/STARTER CABLE/parts.html

If that is blown, you will get an alarm and the alternator will not charge the battery. If it is blown, there should be a spare in the cover.

That fuse is normally blown by connecting your battery up backwards...even for a second.

The test I suggested is not totally conclusive but is a quick easy way to see what is going on.

There is a full field test that can be done to indicate whether the diodes or the regulator are bad. I do not want to try to explain how to do that...I do not have the give of words concise enough to explain that without you messing something up.

A local shop may be able to test it, if they have the right connections.

The regulator costs about $125 and the rectifier (diode pack) costs about $135.

Let us hope it is just a fuse.

Mike

PS. I guess I could have just said, check the fuse....and saved all that writing.