How to Wire a Trailer
- 1). Disconnect the main vehicle battery.
- 2). Route a number 8, stranded copper automotive wire from the tow vehicle's engine to the rear bumper.
- 3). Connect the charge line to the vehicle battery.
- 4). Encase the wire with flexible conduit.
- 5). Secure the wire with ultraviolet-protected tie wraps so that it does not sag, chafe the chassis or get exposed to a high heat source such as the exhaust system.
- 6). Connect the wire to one side of a 50-ampere circuit breaker mounted either on the fender well or engine fire wall. Use a ring terminal.
- 7). Connect another length of wire to the other side of the 50-ampere circuit breaker and connect the other end to the battery terminal on the alternator.
- 8). Ground the wire by attaching it somewhere on the chassis, with at least a 1/4-inch bolt and corresponding ring terminal.
- 9). Plug it in so that the tow vehicle alternator can charge the trailer batteries.
- 10
Check the brake lights, taillights and backup lights with a 12-volt test light or a multimeter. - 11
Probe the wires until you detect current. - 12
Use quick connectors and number 16 automotive wire on all the lights that require it.
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