Boat: 91 Sundowner 255, 5.7 OMC King Cobra. 337 Hours. Prestolite alternator with 5 wires on back (sense, excite, battery, AC, and ground)
Scenario: Bought boat in April. Boat was overcharging - 16.5 volts underway. My VHF wouldnt work, kept on saying "high volts" so I had the alternators internal voltage regulator replaced.
Shop bench tested alternator after and said it works fine, not overcharging for them. Re-install it on boat, still over charging!
I probed the sense and excite wire. Per the OMC manual, the sense and excite leads should have the same voltage as the battery, well my sense and excite wires read 9.65v, whereas my batteries read 12.5v each. So Im losing 3v somewhere.
Traced the wire back to the assist solenoid for the starter. Its 9.65v there too.
Can somebody help me out .. I dont know where to go from here.
Should I run a new wire to the batteries? Should I run a new wire to the solenoid? Is the solenoid bad?