Charging Problems

[Old Johnson]

Just got a 91/92 Johnson 70hp model J70TLEIE. Its only putting out 12.4volts but the voltage drops once I turn on the spot lights. With nothing on, it stays at 12.4v and stays running with the battery disconnected. Do i have a charging problem? Is there a voltage regulator or just the stator? Need help before i start spending money in vaun.
Thanks

[Old Johnson]

Not Charging

Could it be the rectifier?

[boats.net]

Check voltage at battery, crank engine over a couple of times to draw battery down then read voltage, start engine and watch voltage should slowly increase, if not test stator output and test rectifier.

[Old Johnson]

The rectifier showed light resistance in both directions. Replaced, 13.8V now.