The arm wire is connected to a relay that acts as a remote switch which is controlled by a button on the Switch Pro head unit. The relay just connects the red power wire in the remote cable back together to arm the winch switch.
There is a small LED pointed slightly off angle to not bother your eyes as much beside the switch. It does not light up until the switch is hot and able to run the winch since it gets power from the output side of the red wire which is hot from the winch.
Plugging in the remote won't turn the light on, pushing the arm button won't turn the light on. The arm button has to be pushed and the remote has to be plugged into the winch before the indicator tells you it is good to go. No light, no winch from in the cab control.
View attachment 552022