Car Stereos: ac controls not illuminated..., stereo head unit, warning lights

Question
OK,about two weeks ago, I had a new stereo head unit installed in my 03 cavalier(4 door), and now my ac controls wont illuminate. they lit up even when there was no head unit at all. but after the new one was put in, they wont. They had to put a new door chime thing in to install the head unit. what can i do about this? new battery? mine is old. sometimes my warning lights check engine, brights, come on randomely too.

Answer
Hi John,

It almost certainly sounds like during the installation process, some wires got crossed and/or disconnected.  It's entirely possible that their connections were already weak and/or corroded, and this was just the final tap they needed to die.  If you did the install yourself, pull the deck back out, and check the wiring.  If it was installed by someone else, take it back to them and tell them something wasn't done right; they should fix it for you.

Justin