When they are completely out the buzzer, parking brake, low air, and front drive IN lamps were inoperational. On a failsafe unit that is somewhat operational a variety of unusual behavior could occur. I have seen soldered boards come back after years in the automotive field and stuff happens. For Sale Price: USD $165,000. Fully Custom Built by Stretch Customs 1984 Peterbilt 359, Custom Long Hood, 400 3406B Caterpillar Engine, 15 Speed Eaton Transmission, 3.55 Rear End Ratio, Low Air Suspension, 318" Wheelbase, 11R22... See More Details.