Volvo Repair: dash lights, dash lights, dimmer switch

Question
My dash, shift, and instrument  lights recently went out after I installed a radio.I tested the fuses and non are blown.I'm thinking maybe I disconnected a wire(hopefully).
Any suggestions on what else Ishould check.
I've done to different radio installs on the same car and I've never run into this problem.
thanks for your help

Answer
you failed to mention a year or model.in any case I would go back and check all that you have done 99% of the time if it worked before you touched it then usually whatever you have done has caused the problem.also be sure the dimmer switch for the lights has not been turned down.you may have the light wire for the radio connected wrong or not at all and it is shoring out.