Only one -12V Battery cable to batteries on twin outboards

[Sardinia306Canyon]

Hey fellow GW owners.

I wanted finally to install the two Victron SmartShunt i bought to monitor my 3 batteries on my 2011 306 Canyon, but run in some issues.
I could install the two SmartShunts and the one for the single port engine battery seems to work while the twin battery Stbd and house batteries bank works, not not as supposed.

I am not sure if the problem that the Stbd+House SmartShunt does not work as supposed as i have only one negative 12V cable coming from the stern and it's connected to the port side outboard, but i could not find the negative cable from the stbd engine going to one of the two Stbd+House batteriy bank.

All 3 batteries are interconnected with short jumper cables:
Thick, black negative cable from port engine (i guess) comes from the port side conduit and goes to port side battery
1 short jumper cable goes to 1st battery negative of the twin batteries
2nd short jumper cable goes to the 2nd battery negative
So far so good, all 3 batteries -12 volt are connected

But what left me irritated that there is no second negative cable from the stbd engine to be connected to the stbd+house bank???
I checked in the transom area and the two cables from the outboard are there and the cable coming from the conduit to the port side battery is another type of cable, so there must be either a negative bus bar or GW crimped a extension as Yamaha cables are probably too short to reach the console area.

Both engines start flawless, so stbd outboard must have a connection to one of the 3 batteries negative post, but where?
Does GW install somewhere hidden a negative bus bar where the two negative cables from the two outboards go and from there only one negative cable goes to the batteries?

Chris

 

[SkunkBoat]

Yammie always have a two-wire power (starter) cable. They peel them apart to go to switch or battery. If you follow the +12 wire (has a stripe) back toward the motor you will find it attached to the -12 wire.

 

[Sardinia306Canyon]

Thansk SkunkBoat.
Yes i know that, other Suzukis are the same.
I can see both Yamaha cables and it seems they go in a conduit near the battery switches box, but only one comes out under the console and its another type of able so i guess that someone made a extension.

You can see them and the one with the white stripe goes to the battery switches box and the other -12V seem to go in a conduit.



Boat and Motors are 2011 but i am not sure if boat came to Italy without outboards and importer rigged the engines and made this cable mess or if GW made that what i would exclude.

I will pull the battery switch box to see if there is a negative busbar what would explain only one cable.

Chris

 

[Sardinia306Canyon]

I found it!
There is a bolt on the bulkhead in front of the battery switch box where all negatives are collected and from there the single cable will run to the batteries. To access the bolt and the cables the battery has to be removed.
Chris