Abstract: A body member has a number of electrically conducting inlet-outlet connectors or contacts arranged for plug-in attachment with junction portions of a vehicle electrical system having individual power circuits and associated light circuits. A separate visual indicator, such as a light emitting diode, is associated with each inlet-outlet connector. The body member includes a ground circuit therein whereby circuits to the indicators are completed without an outside ground. At least one of the inlet-outlet connectors has a removable portion whereby upon removal thereof, one or more light circuits can be isolated from its power source if desired. As a further concept of the invention, the device is arranged to receive one or more detachable jumpers to provide power from a functioning power circuit to a circuit that has lost its power.