2003 BF200 Voltage gauge was 14 volt, now shows 13 volt on gauge

2003 BF200 Voltage gauge was 14 volt, now shows 13 volt on gauge. I had replaced a battery, went out on a trip, noticed that anytime I engaged a device there would be a spike on the gauge and it would sit at around 13 volts on the gauge. Took the boat home went to troubleshoot and noticed that one of the ground wires was not grounded to the battery. I had that put in place but the gauge still shows as 13 volt but does not spike initiating any devices.

I'm hoping this is not signs to come that I might have damaged something in the process of not grounding the panel wires. Everything seems to be working fine, including the motor.

Beg, borrow, or steal a good digital voltmeter. Measure your battery voltage while engine is off. It should be around 12.3 to 12.5 volts. Start your engine, rev it up to about 1500 rpm in neutral. Then measure voltage on battery again. It should be between 13.6 and 14.6 volts. If that is the case, then your alternator is putting out the correct voltage.

A quirk with the 200/225 is that the gauge reads the voltage from the ECM. For some reason, that voltage will be 0.8 to 1.0 volts lower than what you read on the battery. Between that, and having to cycle through modes on the Honda digital gauge to get the voltage readout, I installed a separate analog voltmeter gage and ran it directly to the battery so I could see alternator performance at a glance. That was a fairly inexpensive investment in piece of mind.

Thanks for the reply. I have a small volt meter that I didn't bring to last trip so I will test this weekend should be accurate to .x . I don't seem to be losing power, so the gauge might be off when I didn't ground it properly. I had livewell, 3 deck lights, plus court lights, washdown pump and music running to see if the charge wasn't keeping up and I didnt' see the voltmeter drop, nor battery drain down.

I had a second battery that I left off on perko just in case. I'll definetely test, but let's say that the charge is less then 13.6, what would need to be replaced? My brother mentioned the stator might need to be replaced or another part, not necessarily the alternator. Thanks.

On the 200 4-stroke, all the juice comes from the alternator. If you are not getting the 13.6 +/- off the alternator, then the first thing you do is thoroughly clean all the connections between the alternator and battery - including the main battery terminals. Measure resistence between the alternator caseing and battery ground - it should be very close to zero. If not, the alternator is not grounded properly. If none of that gets the voltage up, then consider having the alternator rebuilt. There is a procedure for doing that in the shop manual, but I would likely rely on an automotive rebuild shop to do that. If you have it rebuilt, be sure to tell the shop that it is for an outboard.