Back lights on Climate control are out with aftermarket radio install

The back lights on the buttons on the climate control no longer light up.  Seems like this started happening when I installed an aftermarket radio.  Any suggestions?

There is a purple wire that is supposed to control the dimmer on the climate control screen. Not sure about the buttons. My guess is that you knocked something loose. I hate to say it but I would pull it and double check. Unfortunately I don't have a wiring diagram, so I can't help there.

My screen lights up fine, it's the buttons back lights that are not working.