One battery is a starter for a single engine and the 2 batteries are wired in parallel. The two in parallel start one engine and powers you accessories. The factory set up on my04 SF has the switch wired to the #1 position to the single and parallel wired to the #2 switch positon. I leave mine set to #1 on the port and #2 on the starboard. This gives you flexibility to be able to still start your engines is one battery is dead. Never switch the batteries by turning the switch through off if the engine is running. Good luck!
Mine has three batteries, and three switches. Two batteries dedicated to the two motors (individually or together), and both of them are isolated but charge the house battery. I though this was normal.
"aux charging cable" - does this mean Yamaha has the standard battery cable that connects to your main starting battery but also a 2nd "aux" cable that could charge a different battery (if it wasn't in parallel) ?Both of those Yamahas are going to have auxiliary charging cables, and you never know what the original rigger, or the previous owner, has done with them, until you open up those battery switches and diagram all your connections for future reference.
On Myotherboat, the switches are not labelled. I know which motor is powered by which switch but as to whether the starboard switch is number 1 or number 2 is not clear.Meletong: Good posting. It caused me to go back and read my manual more carefully. My 2007 manual reads like your 2005. Battery select switch position 1 powers the starboard engine and the house battery.
I do a lot of live-bait drift fishing with the live well running. I tend to alternate which engine I keep running so that the livewell pump doesn't run down a battery. Now that I think about it, running the port engine while drifting offers no protection to the batteries being discharged.