Opened the pack/z3d file, stripped out the other light bars and textures except for the one I wanted, merged it into the project, moved it into place and scaled it to suit. Created two dummies for extra_1 and extra_4, compounded etc. As far as I'm aware I hadn't rotated anything at all, but since they haven't worked in game I've reset the axis in every way I thought possible.
I created new dummies, relocated and rotated several times to test then copied the axis from the newly located/rotated dummies to the existing dummies used for the bar but I still can't get them lighting forward. The only change I saw during this testing was the takedown, which was then facing downward. I used another set of lights from a different pack, this time merging them straight in and placing them and they don't light forwards either.
Do you think it's worth me remerging the original pack with no edits to see if the problem still exists?