I have a 2000 Merc 50HP 4 Stroke on a 21' Pontoon boat. My problem is with the charging system. When I start the motor the charging rate is 12 -13 amps. After a while when the motor gets warmed up if I happen to hit the trim switch the charging rate goes to 0, and will not start charging again until I stop the motor and restart. I have replaced the stator, the voltage regulator and a couple of sensors and installed a new battery--still does the same thing. When the needle goes to zero on volt meter, the RPM needle is erratic and the trim will not work. Any suggestions?