Just wanted mention how I did the lights on my tractor, and other powered items.
I first created a new 12 volt-30 amp circuit by using a 30 amp circuit breaker, a 30 amp relay, and 10 gauge wire. The relay is "triggered" from a fuse in the fuse box that's powered only when the key is ON so no accessory can be left on to kill the battery.
The lights are 50 watt Hobbs units with trapezoidal pattern-a great compromise between spot and flood patterns. The xenon strobe is a "extra" one from work. The 4 switches are rated at 20 amp each, the two front lights are on one switch, the two rear on another, the strobe on the third and finally the rear 12V power outlet on the fourth. These are water resistant switches from a marine supply store.
Later I added the joystick handle to control the solenoid diverter valve for my grapple, and also a horn. These required the addition of two more relays since the switches in the handle cannot handle any real current.
I am a firm believer in not adding anything extra to the factory wiring harness-due to cost, they are only sized for exactly what the OEM supplies and no more, that is why I feel it's important to add a new circuit for any upgrades.
These pictures are not the greatest I am sorry to say-but here they are: