How to Make Trailer Lights Work Without Hooking Them Up to a Vehicle

In order for the trailer lights to illuminate without actually being connected to a vehicle, they must be wired to a power source. To accomplish this task, connect wires to the positive and negative power leads of the trailer lights. If the trailer lights are modern and adhere to electrical standards, the power leads should be black (for the negative/ground lead) and red (for the positive lead.) Depending on whether the trailer lights were purchased as part of a kit, electrical wires may already be connected to the power leads.

If the lights will need to be turned on and off without physically disconnecting them from the battery, it will be necessary to install a toggle switch. A toggle switch is readily available from local automotive or electronics shops, and should offer two terminals for wire connection. To install the toggle switch, connect the red (positive) lead from the trailer lights to one terminal on the toggle switch, then solder the wire in place. Connect another length of wire to the other terminal of the switch, also soldering that wire in place.

With two wires extending from trailer lights, the wires are ready for connection to a power source. Since the lights are designed to work on a 12-volt automotive system, the ideal power source is a 12-volt car battery available from any local automotive or chain retail store. The wires can be connected to the battery using electrical tape to secure them in place; for a more secure and professional connection, though, first connect the wires to automotive battery terminals and then secure the terminals to the battery posts. Once the wires are secured to the battery, activate the toggle switch installed in Section Two above to illuminate the trailer lights without hooking them up to a vehicle.