In my 02 when i have my lights on the back tail lights are supposed to be illuminated. the one is lit but the other is'nt. once the car warms up for a bit the light turns on. this is'nt the brake light its the tail light. i don't know why the light comes on later when the car is warmed up? any thoughts?

 

Heat causes expansion. Maybe a wire or bulb is slightly loose and warmth expands the connection allowing it to work? You can always check for corrosion on the light connections.