It is a different independent system from the 12v lighting. If you ordered a trailer with 110v lighting, typical routing works like this...
1. Exterior "Motor base plug" this is a weather tight female plug that allows you to hook up 110v - 220v ac with whatever plug configuration that is needed for the amount of "stuff" that you are going to run. If all you are running is 2 - 110v light fixtures, a standard 110v female plug is all that is necessary. This plug is mounted on the exterior of the trailer near where you expect to hook up a generator or a "shore cord" to a building or other connection point.
2. Interior disconnect. This is the first stop after the motorbase plug. This may be a standard type "breaker box" or a simple master disconnect breaker. This is a safety feature to prevent overloading the circuit. This also may be 110v or 220v depending on your load potential.
3. Interior Wiring and fixtures. This goes to outlets, switches, lights, AC/units or whatever else you have that you need to power. - Ditto on the cold weather ballast! Otherwise what's the point?
To run this type of system, you have to have a 110v power source such as a house, building, light pole in a parking lot etc... or bring your own generator. I use the small Honda 110v suitcase generators. The one that I have is 1000 watts. More than enough for lights.
You could have a 12v battery charger wired in so that once 110 power is supplied, it automatically starts charging the house battery or the truck battery, but this would be the only "cross-over" between the systems that I can thing of.
On another thought, you could try and run an inverter to try and power some 110v lights, but that will run your 12v truck and or house battery down quick. But I suppose that would be a possibility. I have thought about this in my trailers but you definately would need to run the tow vehicle engine or you'd have a dead battery when you wanted to leave.
