. . . The Home Deput has everything you need and you can buy the wire pretty inexpensively in 100' rolls. Get one roll of black and one of white should do the whole trailer.
Great advice from Greg, but I should add a couple things.
First, most of the 12 volt wiring in your trailer should be done with 12 or 14 gauge stranded wire. (I use 12 gauge in the new circuits I run.) Some places -- RV, Marine and some hardware supply stores included -- have wiring where the black and white wires are joined together very much like the two sets of wires in a cheap household extension cord. If they have it the electrical
department people at the store should know what this is and where you can find it.
Because they may carry higher electrical
loads some wiring in your trailer should be done with thicker, 10 gauge stranded wire. This includes the wiring from the battery
to the converter and from the tow vehicle charging lines to the trailer.
Next (and don't let this scare you, it's really pretty simple), most trailers have three or four electrical
One is the 12v system that powers the 12v lights
, fan(s) furnace
, and so on inside
The second 12v electrical system connects your tow vehicle's brake and indicator lights
to your trailer, so when you signal a turn or hit the brakes
, the lights on the outside of your trailer blink like the ones on your tow vehicle.
Many trailers have electric brakes
, which are very nice to have and require their own wiring that connects to the tow vehicle, too.
All-in-all 12V wiring is pretty simple to do and, as long as you install fuses in each circuit, very safe.
The last electrical system is the 110v AC system that powers the 110 outlets and any 110v AC appliances, such as the "converter," which charges the battery
and "converts" the 110v power to 12v to power the 12V stuff inside your trailer and charge the battery
. Your trailer may have other 110V goodies like 110V outlets to plug things into, 110v lights, an air conditioner, propane/110v refrigerator
, and an electric or propane/electric water heater.
110V AC wiring is reasonably easy to do, but unlike 12v wiring it can be very dangerous if done wrong. My suggestion is you find an friendly electrician or hanyman who is willing to explain how things need to be done and inspect your work to make sure your wiring job is done safely.