My fisher plows are the old speedcast conventional style plows with belt drive hydros .
When i wire up my plow setup lights i use a few relays . 1 turns on with marker light on . This lets me drive with marker lights on the truck . Then the high/low beam switch still works and lets me feed the plow lights off this way . Then when not plowing a master switch between the marker light trigger to relay 1 . No accidental double headlights .
www.plowsite.com has lots of info over there . And manufacturer specific section with each plow maker having there own section .
Decent guys there . Same screen name for me there and 99% of other forums i am on .