TO-20 Wiring Loom

What were the period correct connector end types, and wire loom mesh for my 1949 TO-20?

There is some 16, 14, and some 12 gauge wire as I recall. It is all cloth covered with some wrapped in tape to form the harness and some in asphalt covered cloth loom. Where loom is used pieces of black rubber tubing is stretched over the terminal and wire to form a sleeve. Black surgical tubing in multiple sizes is used to make these sleeves. The terminals are uninsulated and soldered to the wire, actually dip soldered not soldered with a soldering iron. The rubber tubing forms the sleeves. Terminals used include ring terminals of various sizes, spade terminals and flag style spade terminals.

The original TO-20 wiring is for a battery charge light indicator but there is a factory suggested modification to add an ammeter. The original wiring harness also includes the bulb socket that plugs into the red indicator light housing. There is one wiring harness for the tractor and a wiring harness for the lights, if the tractor is equipped with lights. The light wiring consists of a front section which includes two pieces of tubing, brake tubing actually that runs along the left side of the oil pan and then goes up to the headlights. There is a rear main that goes back to the area of the hydraulic lift lever and then splits into two harnesses. One going to the left fender/taillight and the other going to the right fender/work light.

There are multiple style wire clips used to secure the harness. The light harness uses the large size bullet connectors and female bullet connector sleeves to connect the wires to the lights, and to each other. Most of the wiring clips are available today as reproductions, and some you have to make or find as salvage parts.

Given the materials needed to duplicate the original harness I recommend purchasing the reproduction wiring harnesses made by Agri-Services. When you consider the materials needed to duplicate the original harnesses and the beautiful work they do, it doesn’t pay to make them yourself.