Modding And Hacking A Christmas Light Controller


For under $10 you can buy christmas light sets that flash the lights in different patterns. These sets have a small controller that animates the lights. The light set I chose cost $7.99 and were purchased from Big Lots. The lights can be removed from the controller and plugs installed.


This project works with items that run off of AC mains. Only qualified persons should consider attempting this project. This project is meant as a guide. Your controller may be different from mine.

The Parts List

  • 1 x set of chasing Christmas lights
  • 3 x green multi outlet extension cord
  • 6 x crimp butt connectors


  • Wire cutters
  • Wire strippers
  • Crimp tool

Prepping The Controller

1. Remove the lights from the packaging.
2. Identify the main power leads going into the controller. It should be two wires connected to the AC plug. You may want to place some tape on these wires to identify them. We will not be altering these connections.
3. Next we need to identify the wires connected to the lights. Follow each wire to the first light it is connected to. We are going to leave one light connected to each wire. This will let us identify each channel. Cut the wire that is connected between light 1 and light 2. The controller I had gave me three channels. So I had three lights.
4. The last wire to cut is the return wire for all the lights. About 12 inches from the controller cut the wire. Strip this wire back 1/4 inch.

Prepping The Extension Cords

1. Cut the AC plugs off the extension cords. You should be left with the AC receptacles at the other end.
2. Separate the cord back 2 to 3 inches.
3. Strip each wire back about a 1/4 inch.

Putting It Together

I bet you’re wondering why we left one light connected to each channel. Its an easy way to identify the wires.
1. Twist together the wire without a light connected and one wire from each extension cord. Using a crimp connector secure the connection. This forms our common wire.
2. For each of the wires with a light connected do the following. Cut the light off the wire and strip the wire back 1/4 inch. Twist this wire with the un-crimped wire from one of the extension cords. Using a crimp terminal secure the connection.

Notes About LED Lights

Some sets of LED Christmas lights will work with the controllers. The LED rope lights sold by Costco work fine. LED light sets with 35 lights work fine. Home Depot is also selling LED lights that work as well.
The controller rectifies the AC into pulsating DC. Many LED light sets have half the LEDs wired to handle one half of the AC cycle. And the other half of LEDs are wired to handle the other half of the AC cycle.

How Many Lights Can Be Connected

Many controllers were design to run 150 to 200 lights. My controller ran 150 lights and drew 0.6A of current. My controller has 3 channels. That works out to 0.2A per string of lights.
Using standard Christmas light limits what you can do. At 0.2A per channel the max number of bulbs would be 50. That’s only one string of lights per channel.
Using LED Christmas lights gives you a great show. A string of 50 LED lights I have use 0.05A of current. That means that we can use 4 strings of lights per channel. That’s 200 LED lights per channel or 600 LED lights per controller.


This project was a great way to animate my holiday lights. Don’t forget to check those after Christmas sales for the best deals.

Notify of
Inline Feedbacks
View all comments