Sounds like a simple on off switch in the cab for the brown and red sitting next to the momentary up down switch for your 'trigger' switch.This is what I use Incab to start and operate my Allbright solenoids for the 8274I use carling switches.
I have a big isolation solenoid after my second battery. This feeds the the winch, controls and all my extras. The isolation switch cuts this killing all power to the winch. Even if the winch solenoid sticks i can stop it.