Abstract: A vehicle light testing system is provided for testing the lighting systems of a vehicle having a plurality of lights (which have different operating functions). The testing system includes an arrangement for scanning the plurality of lights in a predetermined scanning sequence. This scanning allows a single testing operator to check the different operating functions of the lights in a single trip around the vehicle. Thus, the scanning sequence can progress from the left turn signal to the brake lights to the right turn signal (and then repeat the cycle again) so that an operator in the back of the vehicle can watch the lights progress through this sequence. The system also includes a number of other features concerned with the testing of vehicle lights in conjunction with the scanning feature, including detection of shorts, bad grounds, and low testing battery voltage, as well as a "freeze" feature and a convenient system status indicator arrangement.