I am going to assume you have a rider backrest. That is the remote adjuster that sets the fore or aft position of the backrest. Post a photo of the seat if you would. On the right side of the receptacle the backrest plugs into there is a lever that enables removal.
Kurt
Yep, had it on my '15
2021 CVO TriGlide - Sunset Orange & Black
Life's journey is not to arrive at the grave in a well-preserved body, but to skid in sideways, totally worn out, shouting...Holy Sh!t What a ride!