I have two stroke 2004 90 Yamaha that once battery is fully charged, charges over 16 volts (voltage goes over 17 at times) . If I turn on a small load or if the battery is somewhat discharged its around 14v. I have checked the basic battery connections by checking for voltage drops between battery negative terminal and the engine block and across the positive terminal back to the outboard connection. I tried replacing the regulator and lost that $100 gamble. This thing has done this since new and doesn't really fry the battery. It seems the voltage is high but with low current which is evidenced by its inability to maintain such voltage with any load on it. The battery life is acceptable but my VHF shuts down from an over voltage protection and I've burned holes in LCD displays in multiple GPS/fishfinders. It's getting too costly to ignore any longer. For information purposes it has separate Yamaha analog tach and voltmeter. It appears that there is an intermediate/adapter harness between the ignition and the guages. I have also checked the regulator black ground wire to block and other regulator to harness connections good. All volt readings were taken with professional grade Fluke multimeter. Any help would be greatly appreciated. I could probably fix this if I had a schematic and a better understanding of outboard charging systems. thanks!
