Toyota Repair: Interior Lights 95 Corolla, light fuse, multifunction switch

Question
Hi Ted,
A friend of mine installed an after market radio in my car and the next night when i turned on my headlights, they went on, but my dash illuminating lights didnt and neither did the shifter console lights.  (The warning lights on the dash work.)  I've checked the fuses, taken apart the dash and power is going to the bulbs and away from them, the bulbs are good, checked the wiring to the radio to the best of my knowledge, they seem to be ok.  
I just heard it could be a short in the multifunction switch(turn signal/headlights) from the naked eye it looks ok, but i didnt try to look further b/c of the airbag and wanting an opinion of a knowledgible person.
Any suggestions, ideas?  
Thanks a lot for your time, i appreciate it greatly,
Jean

Answer
Since you didn't have this problem before I assume that it has something to do with the radio installation, the dash lights are on the same circuit as the tail lights so I need to know if the tail lights are working or not, there are a couple of possibilities, either your friend cut a wire or something shorted out and blew the tail light fuse, so check for a blown tail fuse and let me know if the tailights work.