I put rear detachable parts on my '07 Night Train - Then I put on my detachable sissy bay. One side will not lock completly into place,
Any suggestions on how to fix this?

 

Try pulling down on that locking clip. Sometimes they dont sping down.

 

Spread open the base of it with your hands as you're trying to lock it in place; I have to do it each time I put mine on.

 

same for me as aviscomi, sometimes will pop in place with no interaction, other times not. I have two different detachables, the high upright sissy bar goes in a lot smoother.

 

I have to spread my plates slightly as i put on my detachable backrest to get it to lock

brent

 

dito on spread.
side note: i found a way to not have to relocate the turn signals. with a slight modification to the side plates you can keep the turn signals where they are.
i just shaved them flat and now they slide in front of the turn signal