Wire termination
By Dan Brotzman
February 2010
At some point in time, we are all going to have to make a new wire connection with a wire and connector from a selection of connectors and a wire of the size and color we choose.The trick is to make our wire and connector look like a factory connection.In Photo 1, we can see one factory wire attached to this light and one wire that needed to be made on our own because Deere’s practice of part number substitutions often leads to parts that are nowhere close to the original part. On this John Deere 4230, all of the wiring harnesses were replaced with new wire harnesses from Deere and the result was frustrating and disappointing to say the least.
The solution, fortunately, is quite easy and nearly free of cost. When done correctly, the results will look just like a factory harness connection. The key is to use wire with the correct insulation color, the correct style electrical connector and a product called “shrink tube.” Shrink tube is a product that shrinks when heated and usually comes in 10 or 12 inch lengths that you can cut to the length you wish. In Photo 1, we can see a light with one factory wire connection and one wire that is not a factory connection. We have a choice here—we can either leave it as is or we can use shrink tube to make both connections look factory.
After you have your wire cut to the correct length, the next critical step is to cut your shrink tube to the length desired and slip it over the wire before you crimp or solder the connector onto the wire (Photo 2). The correct length will cover the connector and leave enough to extend beyond the connector about the same length as you used to cover the connector. With the shrink tube in place, you can attach the style connector that is needed (eyelet, spade, fork, etc.). Electrical connectors usually come as crimp on or solder on.
With the correct style connector attached, next slide the shrink tube down over the new connector with the shrink tube extended just about 1/32nd inch beyond the end of the connector insulation (Photo 3). To reduce the shrink tube down, you can use several sources of heat. A common match will work as well as a small propane torch or a commercial heat gun or your Bic lighter. Heat the shrink tube until it shrinks down tightly to the connector and wire (Photo 4). The result is a connection that exactly duplicates a factory harness. In reality, harness makers use the exact same process as we just performed.
When you attach your wires to whatever device they will be used to operate, you will enjoy knowing you have just completed a connection that will perform, and last, just like a factory made harness. In Photo 5, both of these wires were made using the process we just covered here. While this is a very simple process, the end result will make the difference between a mediocre and professional looking job. It does not matter if you are working on old or new equipment, you will want the end result to be the best it can be. With this straightforward process, you will have the look of a factory harness even when a factory harness isn’t available and a look that will pass with even the most critical observers.
You can purchase shrink tube at any automotive supply store, electrical supply store, most hardware stores and many discount surplus discount stores. As always, enjoy this passion to the best of your ability. Everyone will enjoy and benefit from your efforts.
