Mopar wiring code information
Very small wire that is Solid in color is 18ga.
Small wire that is Solid base color and 1 stitch of tracer color (either Black or White) is 16ga.
Medium wire that is Solid base color and 2 stitchs of tracer color (either Black or White) is 14ga.
Large wire that is Solid base color and 3 stitchs of tracer color (either Black or White) is 12ga.
Large wire that is Solid in color is 10ga.
Very Large wire that is Solid base color and 1 stitch of tracer color (either Black or White) is 8ga.
(these Very Large wires would run from Ammeter to Starter, and Ammeter to Ignition Switch)
Also - you may find some wires that are what we call a snakeskin pattern where the base color is two different colors with any number of tracers. The number of tracers on snakeskin wire designates the same gauges as above.(1 tracer=16ga. 2 tracer=14ga...etc...)

This information was supplied by Rhode Island Wiring Service Inc. www.riwire.com