Aidan, Painless Performance did actually have a kit for your application it turns out. Currently sells for $29 to $48 at amazon. Top of the line components and every thing you need plus instructions to make it real easy. Part number is dependent on color of head light wire to take a peak at your bulb connector wires. If you still want to make your own let me know. Obviously the fog mod is just one wire. Read this for proper part number:
NOTE: Kit is compatible with all 1999-2002 GM trucks with low beam daytime running lights. Some 1999 and later trucks wiring did not change. If your headlight wires are tan and green please use kit #30802; if you see purple and yellow please use kit #30821.