Optimax Over Voltage problems

[MJBennett.FL]

I have a 2008 Mercury Optimax 225. I have an intermittent over voltage problem. The set up is a 2 battery system with a blue sea add a battery switch and Si ACR. I have gotten a good amount of over voltage alarms putting me into gaurdian mode lately. I put a new Isolator in it, becuase Mercury said that was the cause after testing. Same problem, until I combine batteries it jumps up to 16-17 volts. Both batteries check out good, I checked alternator output amps at various RPM's and they seem high, 2000 RPM i get 55a 1000 RPM i get 44 amps. Seems high but I dont know exact specs for this motor. Compressor is leaking saltwater on to the alternator, any way to prove its the regulator? Been running in circles on this one, and Mercury doesnt want to believe its the alternator.

 

[ondarvr]

Re: Optimax Over Voltage problems

It sounds like the voltage regulator isn't working. 16-17V is common on an unregulated system, when you combine the batteries they can absorb more voltage so it drops. What do you mean by Mercury doesn't want to believe it's the alternator, is this the dealer that is fixing it, or is it some kind of a warranty issue they don't want to cover? Checking to see if the alternator is working correctly is rather easy.

 

[Don S]

Re: Optimax Over Voltage problems

I put a new Isolator in it, becuase Mercury said that was the cause after testing. Same problem, until I combine batteries it jumps up to 16-17 volts.

What isolater did you put in? You can't have an isolator and an ACR at the same time.