SEA RAY 1981 310EC VANGUARD BATTERY CONFIGURATION

[kachingz]

I have problems with charging after I had, it turned out, inexperienced goofballs lay up my boat for winter, dropped my boat, wierd electrical issues after re-launch in the spring. I do not remember how the main batteries (3) of the large size are hooked up. I have an onboard charger but only charges one battery, but, it looks like all the cables are connected and the books do not tell you how to hook it up. See attached pic. I am just looking to re-hook it up properly.

 

[glenn property of pam]

you have 2 banks. One is a single 12v battery bank the other is a dual 12v battery bank. If the boat is a single engine then the single battery is for the engine and the dual is for the house. There are so many charger configurations its hard to tell how the batteries are charged. If you have a dual battery switch see if you can find the wires from the charger (if the charger wires are the small set that is connected to the left side battery it sounds like the dual switch has to be set to all for the batteries to charge).
Weird electrical issues are normally caused by a bad dc negative connection so check all of the connections are clean and tight. yours doesn't look shinny and wing nuts on the battery are a no-no unless you are removing the batteries all the time. Lock nuts are the best option as they will not come loose (coat in electrical grease after you have tightened them)
Best advice I can give on one picture and its may be wrong as I can not see the charger or the charger connections.