In the first installment of The DIY Heated Vest, I had just finished testing the wires that will become the heating element portion of the vest. The test was successful and I had a nice warm length of wire that wasn’t too hot to melt the wire, yet warm enough to where you could definitely be toasty when wearing it. This was all very promising, so I was ready to move on to the next part which is attaching the connectors that would hook up to the bike’s electrical system.

For this application I wanted something that would allow easy connect/disconnect but that would still stay together strongly enough for motorcycle use. I got a set of those SAE connectors you see for use on battery tenders and indeed other electric clothing products. These connectors are inexpensive and meet all the other requirements I just outlined. Plus if one already has a battery tender connection on their bike (like I do) then you don’t have to run any new wires for using your vest.

On my bike I have a 12volt cigarette lighter type socket under my passenger seat and I already had a cable that connected this outlet to an SAE connector for connecting my battery tender. This socket sits to the right side of the bike so I decided I would want the jacket connection to be on the back, right side. It turned out later that this was not the ideal placement (one of two mistakes but I’ll get to that shortly).

The following is for informational purposes only and  simply a detail of what I did to create my own do-it-yourself electric vest. I do not claim to be an expert in performing this procedure nor do I make guarantees about the safety or operation of someone else's attempt to create a similar item from the details that follow.  If you are not comfortable working with electricity, soldering equipment, or even needles and thread I would not recommend you attempt to create your own version of what I describe below. That being said, choosing to use the below information means you are doing so at your own risk. I am not responsible if you wreck your vest or liner, damage your bikes electrical system, or set yourself on fire. You have been warned.

Since I now had determined where the connection needed to exit the vest, I went ahead and laid the vest out on a table to determine how I was going to arrange the wiring. I wanted the wire to travel up and down the vest as it crossed from the right side to the left. This presented an issue since the nearly forty feet of wire would take considerable time to  place correctly  and evenly, not to mention the amount of sewing that was going to be required.

To ease the burden on myself (and most certainly Carmen who volunteered to do the sewing) I decided to “half” the length of the heating element. I folded the entire length and twisted the wire together ending up with 18.75 feet of wire. Now the length was more reasonable to deal with! Using some safety pins, I laid where I wanted the wire to run on the inside of the vest (this was the second of the two mistakes I made).

With the wire laid out in a mostly even manner throughout the vest I was able to see how and where I wanted the connector to go. Most SAE connectors will have some decent gauge wire on them already as mine did (16awg I believe) and I only needed a few inches for my connection. If you need to add wire, make sure that 18 awg or heavier is used or it may add too much resistance as well as steal some of the “heat” from your heating wires.

At this point I soldered the SAE connector wires to the heating element wires to make a good solid connection. Once that was done I slid some heat shrink tubing not only over the newly soldered spot, but I also covered the other end of the wire I soldered in Part 1. This end was now at the same point as the connection since I had folded the entire length in half as I describe a couple of paragraphs ago.  With this bundled together and now encased in the heat shrink tubing, I had a nice, neat, and sturdy connection point.

The next thing I did could be considered optional to some, but I considered it necessary and was in fact proven right on my first real world usage. I wanted to be able to turn the vest on or off without having to disconnect and re-connect each time. A switch would obviously be in order, but I wasn’t having much luck finding a suitable switch at my local Radio Shack. There were plenty of toggles and push-button switches but nothing that really seemed to be the right combination of size and capacity. A trip to Lowes took care of this issue with the finding of a simple lamp switch.

We’ve all seen these types of switches for years on lamps and so forth. They’re simple, can handle the amperage easily, and best of all, cheap! The one I used was less than $2.00. These switches are easily added to the wiring connection on the vest by simply opening the switch casing with a screw driver. Then cut one of the conductors of the connecting wire and place the switch casing around the wires.

You will see a path inside the switch for the uncut wire to pass through while there will be two sharp “teeth” that will connect to the cut ends of the cut wire. Once you have placed the wires correctly, you’ll “sandwich” the wires between the switch halves. I learned the hard way not use the screw that holds the switch together to squeeze the casing around the wire (it will break!). Instead push the halves together using your fingers or press it down on a table top by hand to squeeze the two halves together.

With the wiring work completed, the last step is to get it sewn into the vest. I’d also like to pause for a moment to go over the two “mistakes” I made earlier. The first mistake was that I placed the connecting cable coming out of the vest on my right side. I was only thinking of the shortest distance to the outlet on my bike and had not considered needing to reach back and turn it on or off. It’s obviously more difficult to get your right hand free to reach behind you when riding than your left, so keep this in mind when placing your wire connection.

The second item I would do differently is the placement of the wire inside the vest, or rather not on the inside. I found that wires put out enough heat that it can be uncomfortably warm if you only have a single layer (one shirt) between the vest and your skin. If I were to do this again I would run the wires on the outside of the vest.

This brings me to the final step, sewing the wires into the vest. Since I used speaker wire the insulation is rather thick and with it being a two conductor wire that has been “doubled-over” it is really too thick to use a sewing machine in this case. Carmen said she would just sew it in by hand and again the fact I had shortened the length of wire by doubling it over itself made this much easier on her. I could have sewn it in myself by hand but it would have certainly fallen to pieces by now if I had done that.

Carmen suggested that one use a poly/cotton blend of thread for good durability and ease of working with it. Earlier I had laid the wire out using safety pins on the vest so we had a “path” determined for the placement of the wiring. She did a great job and in just a couple of hours it was all in place with plenty of extra thread binding the wires where they leave the vest and go to the switch.

A couple of nights later I was able to test the vest out on a short ride to one of our Cycle Gear movie Nights. It was in the low 40’s (F) I believe and as such I only wore a thin long sleeve t-shirt under my jacket and vest. After just a couple minutes I was rather toasty and had to reach back and turn it back off. Leaving later that evening I went through the same process even though it was colder. This was a successful test but did demonstrate the two “mistakes” I made (switch placement and put the wires on the outside of the vest). I have used it again since and I just make sure I wear a thicker shirt under the vest if I’m going to switch it on. This leads me to just a couple of other things that could be done differently and perhaps for the better.

If I had used a wire with thinner insulation, such as telephone wire, it would most likely have reduced the bulk enough to allow use of a sewing machine instead of hand sewing. This of course only makes sense if you have access to a sewing machine.

Another option would be to add a heat controller (or Heatroller) instead of a switch so that the heat could be adjusted. This would certainly add to the cost with commercial units running from at least $40.00 and up. Real DIY’ers would of course build their own PWM heat controllers from parts for around $20.00 so it can be done on the cheap(er).

So with that I’m going to stick a fork in this one. I’m done! I realize it did take a long time to get from Part one of this article to Part two but I’ve finally made it. Just in time it seems for the weather to be warming up!