I had A few back lights not working to the climate control and clock. I put in new bulbs and they are now light up. But the main display that shows the temperature and other stuff works but doesn't light up at night so you cant see the display. Its a small lcd screen and the light bulb for it looked good. what could be the problem since ever thing else on the climate control works? could it be a relay are something? Again it works can see it at daytime, just no light to see it at night.