I am stumped on this issue. My license plate lights dont work and Im not sure why. I downloaded schematic of lift gate and checked for power at the harnesses. there doesnt appear to be power. That said the buzzer and other lights on same circuit work fine. I am perplexed as I dont know where else to look for the problem. It would appear that it is an obvious open in circuit but connections appear okay from the liftgate back to the harness above ceiling in back cargo area.

 

I have had problems where the wires bend when the hatch or trunk lid opens and closes. Police cars are the worst, they open and close the trunk a minimum of 6 times a day. The problems are the wires themselves.

 

If the fuse is not blown, it sounds like you lost the ground or both hot and ground

Check resistance between the ground in the bulb socket and a known good ground. If it is more than 1 ohm, you've lost the ground.check voltage between the 12v side of the socket to a known good ground. You may actually see 12v.