Bulb help...

[laneo2494]

I put in an aftermarket head unit the other day in my 98 yukon and thought everything was good until I was driving last night and noticed all the lights on my HVAC unit were out. The left side lights of the 4x4 case are also not working. The 2HI and auto 4WD lights dont work, but the 4HI and 4LO light up. I checked all the fuses and even removed the bulbs from the back of the HVAC and they seem to be fine. Any ideas why this is happening? did i mess something up when i put my radio in? any help is appreciated...