Hello I just bought a used chicago 10000 lb winch does it need a solenoid or can I use 12v direct with a switch for on off  

it needs a solenoind as close to the winch as possible or two of em if ya use an old ford starter relay or a gm 82-85 6.2l diesel glow plug relay solenoid, on for in and one for out. some setups require 4 solenoids for em to operate.

the easiest way is to get a milemarker or other solenoid.