I own a 2004 Chevy. Sileraldo 2500HD, when I set the parking brake I lost my dash lights. Checked fuses no help, installed a new headlight switch, no help, and swapped some relays ( headlamp rt to lt) no help. I do have power to the switch but no solid ground.What wire color is direct to ground and/or is there no ground? Any ideas or solutions would be appreaciated.