Travel trailers customarily have three sets of wiring installed. There are the 12-volt circuits which run the mechanical and exterior lighting functions of the trailer, controlled by the trailer hitch harness and the tow vehicle. There are the interior 12-volt circuits for lighting and outlets which are powered by a deep cycle battery. And finally there are interior 120-volt circuits for appliances and outlets powered by a shore connection to a grid. Wiring a travel trailer will usually require the installation of at least the mechanical and exterior lighting circuits and the 12-volt interior circuits, and usually the 120-volt circuits also.
Things You'll Need
- Electrical toolkit
- Four-pin hitch
- Seven-pin hitch optional
- Fuse board
- Circuit breaker board
- Converter charger (optional)
Install the harness which connects the various exterior lights, the electric brakes (if fitted) and the 12-volt charge to the on-board batteries. Run wires to both tail lights, both stop/blinker lights, all running lights, the tag illuminator, the electric brakes, the on-board deep cycle and break-away batteries and a ground to a chassis rail.
Observe the conventional color-coding and American Wire Gauge, or AWG, sizing of the exterior light wires. The coding is white to ground, 10-gauge; blue to electric brakes, 12-gauge; brown to tail lights/running lights/license plate illuminator, 14-gauge; black or black/red to battery charge/12 volt supply, 10-gauge; yellow to left turn/brake light, 14-gauge; green to right turn/brake light, 14-gauge and purple to backup light, 14-gauge.
Plan then install the 12-volt interior circuits for lighting and outlets. Run an eight-gauge red or black wire from the positive terminal of the deep cycle battery to a fuse board, then individually fuse supplies to light switches and lights, outlets and fixed appliances. The correct fuse sizes can be found in instruction manuals or on information stickers attached to each appliance. Use white color-coded wire for all runs to ground. Store the plan with all the other documents relevant to the trailer.
Determine the level of provision required from a 120-volt installation, then draw a plan marking the exact locations of all wires to be installed. Use a six-gauge or heavier cord sleeved in UV- and frost-resistant insulation as a shore connection, and connect it directly to an onboard household circuit breaker board.
Run separate circuits to lighting, to outlets in the living area of the trailer, to Ground Fault Circuit Interrupter outlets in the bathroom and galley and to heavy-demand appliances such as cookers and air conditioners. Install a converter charger to recharge the 12-volt deep cycle battery when the shore power cord is plugged into a grid. Store the plan with all the other documents relevant to the trailer.
Tips & Warnings
- If a complete refurbishment of a trailer is under way, wiring projects are made much easier if they are carried out before interior walls and paneling are installed. Use the plans to ensure no fasteners, such as for cabinets and shelves, are driven through the wiring.
- Use cable clips or plastic zip ties to secure wiring runs where they cannot become trip hazards or come into contact with hot or moving components.
- Most local authorities do not require improvements to trailers to be installed or supervised by a licensed professional so long as the work is not for profit and carried out on personal property. Nonetheless, it is good policy to have a safety inspection carried out by a licensed professional when the wiring projects are complete.
- Photo Credit coach, trailer image by Greg Pickens from Fotolia.com
Travel Trailer Schematic Information
How to Wire a Travel Trailer for Electric. Travel trailers customarily have three sets of wiring installed.
How to Rewire Trailer Lights
How to Rewire a Six-Pin Plug. Camper trailers commonly use six-pin connectors to transfer power from the tow vehicle to the tail...
How to Install an Electrical Outlet in a Trailer
Travel trailers typically have two separate electrical systems: a 120-volt system for use when hooked up to a grid and a 12-volt...
How to Wire a Camper with a Plug Diagram
Wiring a camper to tow a trailer is made easier if the camper already has a plug installed and a plug diagram...
How to Wire a 12 Volt Camper
Camper Trailers.org: 12-volt Wiring Diagrams; ... RV Travel.com: 12 Volt DC Systems; 12 Volt Solar ... Wiring a 12 volt fan is...
How to Hook Up Travel Trailer to a Generator
Trips in travel trailers are much more comfortable with a reliable power source.
How to Trace Wires on Travel Trailers
Troubleshooting electrical problems on travel trailers and vehicles is extremely challenging. The difficultly is that most of the wires are hidden inside...
How to Rewire Trailer Lights
Make sure you put the right lamp on the right side when rewiring trailer lights. Learn how to rewire trailer lights in...
How to Wire up a Travel Trailer 30 Amp Box
How to Wire up a Travel Trailer 30 Amp Box. ... Electrical Wiring & Conduit; Wire Connectors; How to Wire up a...
How to Install Trailer Brake Wiring on a Trailer
Whether you have a travel trailer or one that just ... Trailer Wiring Diagrams; Classic Trailers: ... Wiring to trailer electric brakes...