The easiest way is to access the switch in the door jam. He pushes your door when it closed and spring so they "pop" when the door is open is loaded.

Locate this, and delete, and then use that cable and its cable "signal".

If I remember correctly, it's just a switch of land so you can use that to their land after taking a long 12v + and hook it up to the positive side of the LED. Voila, you have lights that react to their doors.