I ordered 1 of the blue tooth lighting control systems off of e-bay the V3.1M (master) and V3.1S (slave) for just under $100.00
So far I like the system the wire leads are long 24" and 16" simple to install and has some neat flashing light setups programmed that are push button activated.
The thing I like the least is the fact you have to pair the truck and trailer everytime you change trailers
Below are the instructions:
V3.1M
V3.1S
If you have any questions let me know and I will try to answer them for you