I have an 04 TL with manual. my left back up light doesn't come on. bought some bulbs to replace the bulb but still wont come on. switch the bulbs from left to right and the bulbs do come on when plugged on the right side. anyone had the same experience?

 

Could be a bad socket or your harness is bad

 

Follow the wires into the trunk - you'll have to pop the trunk liner off. There's a clip on the left side of the trunk that holds the wires onto the chassis, and it has enough slack so the wires move when the trunk opens and shuts. Under that clip, inspect the wires. I had three wires that had frayed due to the clip being installed too tightly.

 

I had similar problems but more extensive in that even the license plates stopped working. I'll assume the side markers work and it's not a fuse (21).

I had to dig into the left trim panel of the trunk and repair 6 wires that had been severed via a white wire guide that was very tight and clipped the snake of wires that move when opening/closing the trunk.

After doing all this, I have precisely the opposite problem in that the right reverse light doesn't work. I guess I'll need to recheck my work.