Abstract: A system which monitors the functioning of safety and signal light circuits on a trailer and verify the lights are operating properly. The system connects into the signal and safety light circuits of the trailer and includes a unit which can be positioned within view of an operator of the vehicle towing the trailer. The unit has an appropriate visual display which warns the operator if one of the safety or signal light circuits have ailed. The visual display can be light emitting diodes which provide an appropriate visual signal. The unit can also include an audio signaling device to warn of a failure in the signal and safety light circuit.

Abstract: An intravehicular auto harness tester with switch consisting of a first housing unit mountable within or upon the dashboard of a motor vehicle containing three small light emitting diodes with wiring leading thereto and therefrom coupled with one resistor per diode, with such wiring entering the housing unit and leaving it by way of a coaxial cable leading to or from a second housing unit located typically in the trunk of the vehicle with three prongs and female socket pocket at a front end of the second housing unit for interfacing with an intravehicular auto harness power plug and with three female socket pockets and a prong at a rear end thereof for interfacing with a trailer harness plug and with wiring therein running from prongs to socket pockets and via junctions along such wiring also from the front end prongs to wiring in the coaxial cable leading to the diodes and a ground wire within the cable leading via an off/on switch from the diodes to the front end socket pocket of the second housing unit alo

Abstract: An intravehicular auto harness tester consisting of a first housing unit mountable within or upon the dashboard of a motor vehicle containing three small light emitting diodes with wiring one wire per diode leading thereto and then therefrom and ultimately as one wire to ground, coupled with one resistor per diode, with such wiring entering the housing unit and leaving it by way of a coaxial cable leading to a second housing unit located typically in the trunk of the vehicle with the wiring within the coaxial cable being connected within the second housing unit to each of three prongs one wire per prong and with one wire to ground via a female socket pocket all located at a front end of the second housing unit for purposes of interfacing with an intravehicular auto harness power plug.

Abstract: An auto harness integrity tester the components of which are respectively a housing unit protectively holding three male prongs extending from holes in one end thereof adjacent a female socket pocket in this end of the housing unit with wiring running from the prongs, one at a time to one each of three resistors and wiring running from each resistor to one each of three light emitting diodes from each of which a wire leads to a common wire leading to the female socket pocket such that when the instant device is plugged into the end plug of an auto harness, current can run from the harness through the prongs to the diodes and via a prong in the end plug received by the female socket pocket to ground.