You may need to pull codes from the ECU/ECM!
You may also want to have the alternator tested.
As for batteries...... I'm the NAZI on boating forums relating to NEVER making direct battery connections, other than battery cables themselves!
There is no need to do this! IMO.
The rear of your MBSS (main battery selector switch.... in your case, the Perko switch), is the perfect location for any accessory connections.
This dramatically reduces the risk of incorrect battery cable or wire connections when doing R & R of batteries.
It leaves properly color coded main cables ONLY to be dealth with!
The # 1 and # 2 terminals can be considered "Un-Interruptible"!
This is schematically the same as if a direct battery connection..... but completely eliminates small terminal corrosion, as well as the typical "Rat's Nest" that we so often see at/on our batteries.
Great location for bilge pump float switch connection, and/or any pre-set radio memory, for example! (fused of course)
The "common" terminal is an "Interruptible" connection.
This is great if the power source is to be turned OFF when the boat is to be left unattended and the MBSS is turned OFF!
Hope you are able to resolve this, and have no damage!
Good luck with it.
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