'89 Daytona ES- Here's what I know:

Tail lights all work except the back up lights. Lighting harness has a good ground. I've confirmed continuity from the reverse switch on the transmission (violet/black wire) through the engine harness and all the way to the back.

The fuse is good, however I'm not reading any power to the #2 fuse cavity. Of all the options that fuse feeds in addition to the back up lights, this car only has the rear defrost (checking that next). Where I'm lost is all the places the B1 (white wire) goes so I can start tracing that. I'm working with an '88 manual, but so far everything has lined up. Basically I'm hoping someone has had and solved this problem or has suggestions of where to go next before I start tearing out half the dash.