Volt gauge says 15 to 16 v, battery tests at 12v when running.

[BudL1te]

The voltage gauge on my Dash reads anywhere from 14 to 16 volts, but the battery across the terminals is only 12 volts. If the alternator wasn't working I would expect the voltage gauge to drop to 12 or below. Not sure where to start on this? Any advice? It's for a 1987 Sea Ray Mercruiser 5.7 inboard outboard.

 

[dingbat]

A fully charged battery wil run 12.6 to 12.7 volts

Isolate battery (pull positive lead off battery) from electrical system then measure battery again.

 

[BudL1te]

Battery 8s charged, just pulled off charger, it's at 12.6

 

[Scott Danforth]

You may have a bad connection somewhere.

With motor running check voltage at alternator output. If that is higher that what you are reading at the battery, you have a bad connection somewhere

 

[BudL1te]

Decided to take the alternator off to clean the wires, seeing the orange wire Where It Bolts to the alternator was encrusted with rust. Got more than I expected. But at least I believe I found the problem.

 

[BudL1te]

Brushed everything down and was looking good till I noticed one of the terminals was loose, it fell off and no way to connect it back ordered new alternator.