I own a 1999 Chevy Malibu. When the headlights are turned on (Not daytime running lights) The radio display is dark. I am thinking it is a fuse probably one that dims the radio at night but I can't figure out which one it is. I can't find any fuse in the manual about dimming the radio display or anything and that is the only thing that is not working. Its not a big deal more of a nuisance than anything cause at night you can't tell what station you are on or what time it is. Any ideas? Thanks

Is it only the radio which is dimmed or are the HVAC controls dimmed as well ?

It is only the radio. It is completly dark when the headlights are on.

If its only the radio, then it may be something internal to the radio. There is a wire in the wiring harness on the back of the stereo that is specifically the dimmer signal wire. It obviously is sending a signal if the lights are dimming at all (albeit, totally). Someone correct me if I am wrong, but it sounds like there is something, possibly a current limiting resistor, that is burnt out/disconnected in the headunit itself. I'm not sure that even if you knew exactly what it was inside the headunit that repair would be possible.

Thank You for the information.

A possible fix that you may want to try is to disconnect the dimming signal wire from the wiring harness. This would make the headunit stay at it brightest at all times. There should be some information online as to which wire it is. I'll check later this afternoon when I get back if you haven't already located the wire.