For normal operation it's set to "on"
For winching it's set to "combine" if you want to winch with both batteries.
In my FJ60 I have it wired so "off" is stock FJ60 wiring that will start and run on the starting battery.
"On" means the system is on and brings the ACR and second battery loads on-line. It functions as an isolated dual charge system.
"Combine" means both batteries are combined like in a self jump situation.
For winching it's set to "combine" if you want to winch with both batteries.
In my FJ60 I have it wired so "off" is stock FJ60 wiring that will start and run on the starting battery.
"On" means the system is on and brings the ACR and second battery loads on-line. It functions as an isolated dual charge system.
"Combine" means both batteries are combined like in a self jump situation.