1994 BMW 318I - Tail Light Issue
 

Have a 318i BMW 4dr sedan and the passenger tail light won't work. I have tried the blub with no luck. Tried installing a new tail light and still no luck. Everything was working before the battery went in the car from sitting. Any thoughts on things that I should check. Also checked the fuses. HELP! This is so frustrating.

Check the wiring harness in the trunk area. They are known to wear and short, sometimes causing a fire!

It is possible your short there is what drained your battery as well...

Tis don't use the same wiring harness and fortunately (as far as I know anyway) don't catch on fire from this.

Check also the fuse but most likely it can be a wire in the trunk area like Jim said.