I have a 1974 Dodge Class “C” Motor Home. I also have the Wiring Diagram from 1974 Dodge Service Manual. My question is concerning the labeling of the wires in the Diagram. Example: F3-16R and S17-18W. Does the “16” and the “18” represent the gauge of the wire? I know the “R” represents the color RED and the “W” represents the color WHITE.