90AETO 90hp Outboard Year 2000

[timpotty]

I am concerned that after a few minutes of running my outboard the voltage gauge on my Campion 485SS shows high voltage-16 volts plus. Using trim contols dips the voltage but then rises immediately on release. Is my voltage regulator faulty and how do I test it?
Sorry I'm a relative novice but my local boat yards are not very helpful/dim.

[boats.net]

Check all wire connections, battery cables are clean and tight at battery and on engine, wires from regulator are tight, check all ground wire connections on engine. Load test battery to make is in good shape.