Abstract: A system for detecting worn brake linings contains sensors located at predetermined depths in the brake linings. Each brake has a corresponding lamp so a problem with a worn lining can be located. The system contains quick-release connections for each sensor, jumper wires for connecting the two sensors per wheel, resistors, diodes and lamps. The system is self-troubleshooting, and can determine the presence and location of worn brake linings, loose wires, open circuits, shorts, grounds, defective bulbs, and blown fuses. The determination of the presence and location of a problem is made through use of lamps which may be off, glowing at half brilliance, or glowing at full brilliance under specified conditions. When the ignition is off, all the bulbs are off. When the ignition is "on", all the bulbs glow at half brilliance if there are no problems. If all the bulbs are out, it is indicative of a power failure.