[jacob54904]

i have a 2001 gmc sierra 2500 hd. stock from the factory these trucks are set up for the accessory wire to charge the battery, but they are not hooked up. they never have been in the past either. there is a wiring harness you can buy and install to get this wire to work. there is no fuse for it in the fuse boxes. i am not sure where on your truck the harness installs but on mine it is next to the gas tank so it is kind of hard to get at. if you are up to it you could do what i plan on doing and just run a live wire right from the battery and connect to the correct wire on the trailer plug. if you decide to go this route then i would strongly suggest fusing this wire with a 40 to 80 amp fuse. i hope i helped some. good luck