2025 250 Pro XS Connection

[NewEnglandLegend]

Hello, have a question that I keep getting mixed answers on.
Engine is a 2025 250 Pro XS, Serial # 3B464356
My last 2 boats a 2021 and 2023 had the same engine connected to a Bluewater shut off switch (Off, On, Jumper) in back compartment, when the switch is in the Off position, nothing works, Engine and everthing else.
The new boat has the same switch, but the Engine works when switch in Off position.
Engine positive cable connecd directly to starting battery, not to the switch.
Is this something mercury recommend or it should be connected to the switch like my last 2 boats.
Sorry for the long thread!

[EuropeanAM]

Technically, this is a "trick question".

There are TWO power connections for your engine.

The CLEAN POWER (which contains a 5a fuse) is REQUIRED to be connected DIRECTLY to the cranking battery per Mercury's instructions.

The POSITIVE BATTERY CABLE may be attached to a battery switch. In the event that more than one battery is connected to this switch, ALL switched batteries must had a suitable-gauge common bonding ground cable between the negative posts of said batteries.

[NewEnglandLegend]

The clean power (which have the 5A fuse) is connected to the cranking battery.
I only have one cranking battery attached to the switch, so I'm not using the jumper function on the switch because I don't have a second battery to connect to it.
The positive cable from the cranking battery is attached to the switch (Post 1 battery). The switch have 4 posts on the back labeled (post 1 battery, post 1 engine, post 2 battery, post 2 load).
Can I attach the engine positive cable to (Post 1 engine) on the switch so the power is cut off to the engine when the switch is off ?

[EuropeanAM]

Yes, that would be the intended connection method.

[NewEnglandLegend]

Thank you Don!