i had a radio installed, and a week later, the rear parking lights, side markers and license plate lights are out. i changed the bulbs, disconnected the radio and tried the lights again, but it still doesn't work. The turn signals, reverse light and brake lights all work and all the fuses are fine.

Does anyone have any idea on what's wrong or where i should look next?
Is their a fuse for parking lights?

Thanks.
jd