I have a 99 Tahoe 4 door 4x4 old police truck and my back up lamps aren't working I have replaced the bulbs and the neutral safety switch but no luck I was wondering did anyone have any experience with these issues or have a wiring schematic. I have check the fuse for the backup lamps which is the same as the turn fuse from what I understand and my turn signals, brake lamps, park lamps all function properly Thanks ahead for anyone that can shed a little light on the situation