I currently have a 2001. 5 2x4 with the factory fog lights, but I'm looking at a 2001. 5 4X4 model I'm thinking about buying. It doesn't have the fog lights. Does anyone know if the wiring harness is already in place for the lights and all I would have to do is swap out the headlight switch for one optioned for the fog lights? Thanks for any info that can be shed on this.