TRAILER LIGHT TESTING SYSTEM

An apparatus and methods for testing a trailer light system including a trailer connector for coupling a first voltage to a first trailer light and a second voltage to a second trailer light, a transmission state detector for determining a vehicle transmission state, and a trailer interface module for detecting an electrical connection to a trailer at the trailer connection, and for applying the first voltage to the trailer connector and the second voltage to the trailer connector in response to the detection of the electrical connection and the vehicle transmission state being in a park state.