Check the sockets for corrosion, power, ground
Check the wiring for an open
Run a test wire from the tailights to the plate light
Note to the next guy this happens to: The fuse for the plate lights on my Ford Ranger (2000) was *not* in the standard fuse box beside the instrument panel. There's a secondary fuse box under the hood, in a rectangular box close to the corner nearest the driver. It's called the "Power Box" or something similar. You probably checked the wrong fuses.
If the night running lights have failed the bulbs should be checked. Find the bulb housings and remove the parts. After the bulbs are replaced check the lights.
Working brake lights are important for safety reasons while driving. It is important to check all of the wiring, if the brake lights are not working and the fuses and bulbs have been checked.
How about a malfunctioning brake light switch
If a car's lights are not working properly, the fuses should be replaced. The light bulbs should also be replaced if needed.
check the fuse for dash lights
The problem probably wasn't the bulb. The problem is the fuse is blown and needs to be replaced and the problem will be resolved.
check the connection there was a corrosion in the connection of my firebird that was stoping all of the bulbs to work and check the ground on the bulbs if that don't work i would have to say start tracing the wires under the carpet for bad wires but dielectric grese is the tail lights best freind after you get them working. Good luck
More than likely the ballast in the fixture has failed.
There are a couple of reasons why a 2005 Saturn Ion's reverse lights will not work. The fuses may be blown or the light bulbs need to be replaced. Fuses and bulbs can be purchased at any auto parts store.
If the parking/tailight fuse is good - then it may be a bad headlight switch No tail lights but the bulbs are working? Please explain.
take out the bulbs and see if they are burned out.
check that you have double filament bulbs in tail lights