I love to spread Christmas cheer. This year I wanted to do it while commuting around town. I thought what better way then to put a wreath on the front of my truck that lights up with my headlights. I first looked at wreaths that already had lights in them. Most of these were made for 120V (not so car friendly) or were too expensive. After finding wreaths that were cheap without light and small AA battery power LED Christmas lights, I realized I could save some bucks and make this on my own. The hardest part for this build would be connecting to turn on with my headlights. I explain how I did this with my 2008 Toyota Tacoma I can't guarantee this can be done for other makes and models though many may be similar.
Step 1: Gathering Supplies
Led Christmas Lights for a Bike
Old School Car Cell Phone Charger
ATM Fuse Tap (Size depends on make model year of Vehicle I used ATM Mini Fuse Tap)
Wire ( I used about 5 feet of twin Lead)
Step 2: Power Supply
The purpose of the old school car phone charger is to use the 5v regulator to power the LED lights. If you don't have one laying around or tucked into a drawer of old wires they are easily found at thrift stores. I bought the one in the picture for a dollar.
I open the clamshell on of the power supply with the use of a small flat head screwdriver. Inside we can see the regulator circuit that converts the 12V down to 5V as shown in picture 2. The 12V is supplied by the tip via the spring as shown in picture 3. The ground is passed by the spring on the side shown in picture 4. The output of the power supply is the red and black wires shown in picture 5. I unsoldered these parts and cleaned the holes to the best I could shown in picture 6. I found the best way to clean soldered up holes is to melt the solder then quickly tap it on the table. The solder will just fly right out of the hole.
After all the holes were cleaned I then soldered in the twin lead wire on the tip. I put the purple on the 12V and the black on the ground. On the output, I solder in the twin lead wire with the purple on the 5V. The soldering is shown in picture 7. I placed the circuit board back in the shell then clip it back together making sure the wires came out the back and front. I used the original case to protect the electronics. Using liquid tape, I glued the shell together to help seal and hold it. The fusible link on the purple wire just by using the attached crimp connector. I also thought it would be a good idea to put heat shrink on the connection to help hold it on. I then put a hoop connector on the black wire.
Step 3: Connection to LEDs
Before adding wires to the battery case I prepared it to be connected to the wreath via a zip tie. This was done by drill two holes in the battery case about a 1/4 of an inch apart and then put a zip tie through the holes like shown in picture 2. I wanted to keep this a watertight as possible so I covered the holes and zip tie with liquid tape.
I wanted to keep the utility of the batteries as well as add in the supply. In retrospect, it didn't add much functionality and it would have been easier to cut the wires off the battery case and connect them directly to power supply.
I noticed that the switch in the light was a single pole double throw. Meaning it can have two sources to one output. This allowed the ability to switch between batteries and the power supply. I drilled a hole small enough to fit the twin lead wire I put on the output of the power supply. I tried to put the hole as close to the button as possible. After looking at the battery supply I noticed that the switch activated the positive voltage to the LEDs. So to the bare post of the button, I solder the purple wire. I then soldered the black wire to the ground or negative on the battery post. This is shown in picture 4 and 5. It may look like both are purple but that is just how the wire split.
Step 4: Putting LEDs on Wreath
The thing I really didn't like about these LEDs what how stiff the wire was. I felt like when I was unwinding them to put on the wreath it was easy to break the wire or put a bend it damaging the outside insulation. If you can find some stranded wire battery powered LEDs I recommend using them. I did bend them a bit as shown in the picture. To ensure that the insulation was good, I put liquid tape on the part shown in the first picture.
I wanted to make sure the battery case was hidden behind the wreath. So I found the fullest part then used the zip tie to fasten it to the wire part of the wreath. I started wrapping the light by going through the center of the wreath around the outside back through the center. I tried to make the wraps as evenly spaced as I could. I then put batteries in the case to give it a test. I was happy to see I didn't break the wires.
Step 5: Connecting to Vehicle
I come from a long line of backyard mechanics and feel comfortable about this next part. That being stated if you follow the same steps as I did, anyone can make this work. The one thing I would recommend to get is the repair manual for the vehicle you will be working with. I have the Chilton manual for my truck and very much used for this project and others. I looked at this first to see what would be the best way to put a wreath on. This manual showed exactly how the truck headlights were wired and fused. I noticed they have fuse after the main relay. This allowed me to use the fuse tap to connect it to the headlights circuit. If this fuse would have been in line prior to the relay I wouldn't have done something different, but I wouldn't have spliced wires. Cutting wires can be too invasive and cause problems down the road.
I found the correct fuse in the underhood fuse box and replaced it with the fuse tap. I wasn't worried about drawing too much current through the headlight relay as the LEDs only pulled less than 500 mA. I measured to be sure. I also put a 1 amp fuse in the fuse for the LEDs in case something went wrong it wouldn't blow out the relay and lose headlights completely. Lastly, I connected the ground wire (black) to the side wall with the hoop connector. There just happened to be a threaded hole there that I had a bolt that fit on hand. Once this was complete I started the truck and made sure the wreath lights came on and went off with the headlights. I also tested the button on the battery case to see if it would also turn on and off the wreath lights as well. Both worked great. But as I said it would have been easier to just connect the power supply directly to the lights.