look at the ground wire it should be black
Also check the fuse
Have your neutral safety switch checked. If you don't have any bad fuses and you've changed the bulbs, most likely it's your neutral safety switch. It's located on your transmission.
The reverse changed, take a good look at the next one you see.
Reverse light switch.
switch sensor located next to the transmission
Some cars have LED lights, but most use a special light bulb that can be purchased at your next service.
Simple pull back on the electrical connector and disconnect it from the bulb. Next remove the rubber boot that protects the bulb area. Next push down and release the metal spring clip that holds the bulb in place. Remove and replace the bulb with a reverse procedure.
First identify the failed bulb. Open the boot and unclip the nut cover on the exterior fixing. Undo the two nuts ( one outer and one inner). In the side storage compartment, unclip the lamp holder and disconnect the connector(wire) to the failed bulb. Replace the bulb and refit the unit. Bulb sequence: Top most bulb : Stop lights P21 W/5 W Next is the Direction indicator: PY 21 W Next is the reversing lights: P21 W Next is the Fog lights : P21 W
the reverse safety back up switch is located on top of the transmission next to the clutch resivior
it is your bulb board. The thing your bulbs go into. Had the same problem. 10.00 bucks
Most likely a bad bulb or corroded bulb socket. Next check your license plate bulb and socket. Check trailer hitch harness. Check owner's manual to see if there is more than one fuse box. It could also be in the light switch or a short in the wiring. Most likely its a bulb though. See sources and related links below for bulb information.
the socket
The bulb probably just burnt out.. I'm not sure how to change it.
Fuse no 11 in the fusebox next to the battery