Charging System problems with my Mariner 60HP 1992

[Dom_inance]

Hi Guys,

I am hoping someone can help me with this one.

I have a 60HP 1992 Mariner standard (non-bigfoot). Welch Plug Serial Number: 0D121007. A few months ago I installed all new gauges including a tach, voltmeter, fuel gauge and speedo. The engine came with a rectifier (816770). When I connected up my tach I noticed one of the yellow stator wires was disconnected from the tach. I also noticed the yellow wires were a little corroded so I cleaned them up re-cut and soldered new end connectors and reconnected to the rectifier. I ran a new wire from the rectifier straight to the sense post on the new tacho.

I have used the boat several times since. I have also connected up dual batteries with a VSR and an isolator switch, as I wanted to do things properly. Everything was working correctly.

After several times taking the boat out I noticed the volts on the volt meter started to climb above 14 volt and max out the voltmeter! The voltmeter reads up to 16 volt. I also noticed that the tach would show 1100 rmp correctly at idle and 6000 rpm at full throttle, but as it reached 6000 rpm the tacho would zero out whilst the volt meter climbed over normal voltage. As I accelerate so does the voltage to over 16 volt! I have stopped using the boat since as I noticed it was effecting my instruments like my fish finder which would auto cut off due to the high voltage. I am worried as I do not want to boil my batteries or ruin my instruments.

Since then I have been doing my research looking for a solution. Through an exploded diagram I noticed that this model engine has an option for voltage regulator/rectifier (815279T). I have read up on their functionality and thought that this would solve my problem/s, as it would regulate my voltage to the acceptable; approx. 13.7-14.1 volts. I purchased this regulator/rectifier and wired it up. Red wire to battery side of solenoid, sense red wire to battery side of solenoid, black to case ground, yellows to ac out from stator and grey to tacho. I fired the engine up with the new regulator/rectifier and noticed that when the motor heated up and I revved the engine the voltage still climbed over 14 volt and eventually max out the volt meter, I also noticed my tacho has no response! I am puzzled as I know the stator is putting out AC voltage but possibly too much? Can the stator be dead? I have heard of stators dying and showing this by not putting out enough charge but can a stator show signs of dying by putting out too much charge? Also have no idea why there is no tach response?

I have connected a multimeter to show ohm’s across both yellow wires coming from the stator and they show a result of 1.0 which I believe is acceptable. When I connect the multimeter to show voltage I get approx. 16 volts while idling and up to around 30 volt in high revs??

I don’t know where I should go from here. I don’t want to replace one thing and then another guessing where the problem is coming from, because as you'd know stators etc. are expensive. If it is the stator I will replace but don’t know for sure.

Any help would be greatly appreciated.

Thanks,

Dom