1992 Toyota Camry

Electrical problem
1992 Toyota Camry 90,000 miles

My girlfriend has a camry and her dad went to change the stock radio to a new cd player. The radio works fine but the problem is that the lights in the dash where the speedo and everything is dont swith on when the lights are turned on. Does this have something to do with the way he has wired the radio. I have looked at wiring diagrams and he hasnt connected the illumination wire is this needed or would it be another problem. Any advise is much appreaciated.
thanks ryan