I made my own...
I used 4 ford solenoids to make a power in/out switch for the winch on my small crane on a flatbed..It took a few hours with a battery,the 4 solenoids,and a old blower motor I had,and a bunch of wires and alligator clips to figure out which way to hook up all the wires(burned a few wires till I got it right!

)--then when I got it working,I got out my pen and notebook and wrote it down,so I would know where the wires go should I need to replace a solenoid...
I mounted them in a galvanized metal box under the bed--they seem to hold up good,I've used the winch/crane a lot,and stalled it out more than a few times--the solenoids dont seem to mind,but my winch is only a 1500lb size like they use on a quad...
Funny,I was just messing with them yesterday,had to add a new ground wire..--I have put the flatbed/crane onto a trailer made from a 62 GMC 3/4 ton chassis,since the 74 K20 it was on before is headed for the crusher very soon--my back is too--not sure if it was worth all the effort,the flatbed was almost as rotted as the truck!
I have seen the solenoid switch assembly in the Burden Sales catolog( a salvage company) for about 35 bucks,all built and wired--I would have bought one in a heartbeat had I seen it before I built the one I made!--it will cost more for the solenoids than that--and it comes with a hand held remote switch too...
