Adding Interior Lights To Cargo Trailer. The 7 way plug has a 12v power wire. The trailers interior lights are then usually powered from the tow vehicle side of that diode- which prevents the lights from running off of the brake battery.
The trailers interior lights are then usually powered from the tow vehicle side of that diode- which prevents the lights from running off of the brake battery. To do this you would tap into the brown wire on the trailer harness. LED lights are you best bet.
Plus the light switch in the trailer must be turned on.
I would find the 12v terminal and connect to it and possibly maybe add an aux. Your super-insulated trailer conversion will be warm inside without expensive heating systems. I would like to add an auxiliary battery. I would find the 12v terminal and connect to it and possibly maybe add an aux.