2001 SeaRay 310 sundancer issue.

[DarrenC]

Good morning, spent several hours in bildge over last few days. Meter at dash reading 12 volts on port 14 on starboard. When starting port engine battery dead at season start. When I put jumper on started right up. Changed out new battery and starts no problem but alternator still reading 12.3 and battery at 12.3 while running, so I changed alternator with new one. Still 12.3 at battery. I’m thinking a disconnected wire from alternator to battery or ground. Can anyone tell me where to search? Or does anyone have the wire diagram for merc horizon 5.7 mpi? Going in water tomorrow but wanted to see if I could fox it today. Thanks all.

 

[scoflaw]

The feed from the alternator to the battery is the orange wire that connects to the 90 amp fuse on the starter. Ground wire is easy enough to check at alt.

 

[DarrenC]

Good morning, spent several hours in bildge over last few days. Meter at dash reading 12 volts on port 14 on starboard. When starting port engine battery dead at season start. When I put jumper on started right up. Changed out new battery and starts no problem but alternator still reading 12.3 and battery at 12.3 while running, so I changed alternator with new one. Still 12.3 at battery. I’m thinking a disconnected wire from alternator to battery or ground. Can anyone tell me where to search? Or does anyone have the wire diagram for merc horizon 5.7 mpi? Going in water tomorrow but wanted to see if I could fox it today. Thanks all.

 

[DarrenC]

Came across this severely corroded was all green cleaned best I could put back and gauge went almost to 13 at dash from 12. Would this be a voltage regulator?