Grand Prix Display Light

:disappoinI have replaced the display bulb but, no change. Old bulb was checked and showed that it was bad. New bulb, AC/Delco #16208443 checks good as for continuity. Still no display! Everything works fine. I can see the display if I use a flashligh and everything is as it suppose to be. Any suggestions other than buying an aftermarket. This is the second radio I have tried. I bought this radio on Ebay and everything was suppose to work. Everything does except the display. Abs/trac off light is on also. Computer code is C0450 which is the EBTCM. Mechanic is suggesting the Rack and Pinion. Any suggestions or thoughts?