Color Changing Warming Hat Using Arduino

Problem with my circuit

Step 1: Please Help

Im actually writing this to try to get some feedback from some people.

For one of my final projects in school I am making a beanie with color changing fabrics that should heat up and change colors when the temperature outside gets below a certain temperature.

We are getting so far into our project and when it finally becomes time to test it out its failing.

We have rebuilt the circuit twice and we know the code is fine because we have gotten it to work with an LED.

I will post below everything I have done before and hopefully I can get some good feedback.

Thanks!

Step 2: Temperature Sensor

First I set up my temperature sensor in a breadboard and checked to make sure it was working and it was. It was reading temperature perfectly and when head was added the temperature was changing. We also on the breadboard had it so an LED was turning on when the temperature got below a certain point and that was working perfectly too.

Step 3: Changing the LED to the Heading Pad

Now comes the fun part,

We at first tried one transistor that was getting way too hot for how much power was giving off from the circuit so I ended up going with the TIP120. What seems to be happening with my circuit is which ever signal pin is being used is failing which is not allowing power back to my heading pad. We recreated the circuit twice and the same thing happened both time. I did many hours of research to see if this was a common problem but I couldn't ever find a direct answer. We have checked every connection and they are all receiving power so we are having a hard time figuring out what is going on with our signal pin.

If anyone could help that would be awesome.

Thank you!

Step 4: