97 Mariner 150hp Overcharging and No Tach

Boat-ryder

Petty Officer 3rd Class
Joined
May 19, 2012
Messages
87
Hello,

Hoping someone can give some advice, Issue's noticed when trying to fix strange tach readings. The readings I was getting are all over the board. I have the 40 amp duel regulator charging system. All wiring to tach is intact and when testing charging system i found it to be overcharging. After startup and as boat idles voltage checked at battery rises to around 16.2 and never comes back down. This is with a fully charged battery.

The next step in the manual requires a voltmeter capable of 40 amps which i dont have at the moment. Wondering if there are any other test to help determine what is faulty. Before finding the overcharging condition i tried switching tach feed to the other regulator (Grey wire) and got no reading at all. I have the old style voltage regs with clear epoxy.

Thanks
 

Adam21986

Recruit
Joined
Jul 10, 2020
Messages
3
I had a the same issue on my 96 200 EFI Mariner and it turned out to be one of the voltage regulators. Replaced voltage regulator and tach works fine and over charging gone. Hope this helps
 
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