2000 Gmc 2500

Is there any way I can find out if My truck is prewired at the factory for fog lights. I have bought all parts & installed all except the factory switch and dealer won't help. Says to costly for his tech to connect wires to lights, install new switch, and turn on by computer. Can I put in switch, run wires to a relay and wire myself. Lights mounted already, and I have pigtails and New switch. I need more light on the roads.
Thanks for any & all help!!