It’s not the light bulbs. The ambient light sensor (photo cell) has gone bad. A common C4 issue. It is located in the upper left corner of the DIC panel above the buttons for the fuel data and such. You will see a small hole there, the sensor sits in there. I have the same issue. The sensor can be replaced by itself. This outfit does the repair or will send you the part (BATEE.com). Or, like me, you can replace the whole DIC unit. My fuel data buttons were intermittent so I decided to replace the whole thing.
H
