US Patent 7336082 Vehicle circuit tester

A vehicle circuit tester for electrically testing the circuit system of a trailer. The tester can connect to a variety of types of trailers for the purpose of analyzing or monitoring the trailer's circuit system. The tester includes indicators that indicate continuity of the various circuits, thus confirming operability of the trailer lamps. The tester includes wiring connectors in a variety of dimensions and plug configurations, most of which are standardized and widely adopted. As such, the vehicle circuit tester is provided with a plurality of wiring connectors conventionally provided on different sizes and types of trailers. The tester includes probe and ground wires that can be wound up on a reel inside the tester.