I have a 2009 police crown vic and the steering wheel cruise control no longer lights up as well as the back-lighting for the hvac controls. I have been through the fuse panels and can't find anything blown there. I have no idea where to start looking to fix the problem. I can live with the problem, but would rather fix it. My blend door also does not work and am wondering if all three problems are related somehow. I might also note that I think the problems started after installing an aftermarket stereo. I put the factory radio back in to see if it solved the problem...but of course it didn't.

Any ideas would be helpful. Thanks