What guage wire is the standard for trailers with a 7 pin plug. the local NAPA sold me 7 conductor wire with 6 - 12 guage and 1 - 10 guage wire. The problem is that I can not fit the wires into the terminals on the plug, the wires are too large or the terminals are too small. I purchased a 7 pin RV style plug with the flat terminals from NAPA. Are there different RV style plug that accept larger conductors?