99 GMC Yukon 4wd Fuse Box Diagram 99 GMC Yukon 4wd Fuse Box Map Fuse Panel Layout Diagram Parts: starter relay, brake lamp relay, lighting, battery, fuse puller, air relay, A/C relay, fuel pump relay, horn relay, rear defogger, auxiliary fan, heated mirror, ignition switch, diode, glow plug, heated seat, stop lamp, blower.