I need to bring out a 12vdc line to the rear of my tractor for a tow behind sprayer whose motor is rated at 8amps. Wire size of 18 or 20 AWG should be enough and I found two unused, capped electrical harnesses in the rear of the tractor. The first picture shows one at the top of the cab and the second is behind the rear toolbox. Both seem to be at least 20AWG and I assume they are there for some external implement use. I have asked the dealer a few times with no success and the only available service shop manual doesn't show wiring for the Cab model. I can pull fuses to see what circuit they may be part of but was hoping someone on the Forum has gone through this before. Ideally would be best to have a on-off switch among the rocker switches cutouts along the right side armrest. Any advice appreciated.