I have a 1995 75hp merc , regulated system{ I called mercury and they said it does have a regulator}.Problem: Last season the volt gauge intermittently went all the way to 18v { also triggering the warning alarm} and then going back to normal.I ran it anyway , not knowing it could possibly cause further damage.Anyway ,over the winter I put the battery on a charger and the charger gave me a fault code saying the battery had an internal open cell and to replace it.So last week I bought a new battery and ran her.She ran fine all day with the volt gauge where it should be.On the way back in,going through some fairly decent chop and boat pounding the voltage gauge decides to dance around again , jumping to 18v and dropping to normal intermittently.Should I be looking into replaceing the regulator and what would make teh regulator go bad in the first place , if in fact this is the problem. Also , the lights on the console gauges { gas , tach and voltage} all have backlights but they only work when they want.Sometimes only two work , sometimes one , sometimes all three.RPM gauge was also stuck at a low reading even after shutting the motor off. Should I be looking at the regulator or search for a short or loose wire and if so , where would I begin looking for loose wireing? I'm not very mechanically inclined as far as boats so bare with me LOL !! One more thing:If the regulator is bad, should I disconnect the battery even though it is not running??
