The brake light switch may be the culprit.
This is a known problem with the V Rod, where the fluid gets past the hydraulic switch, leaks out and because of the location you do not see fluid anywhere.
If you find this to be the problem be sure to report it to the NHSTB I think it is as this problem is caused (if this is the case with your switch) by defective part used by Harley.
If you go to the dealership and this is th eproblem they will advise "we change these out all the time because they fail".
And yet to date no recall notice to anyone about it.
Recall to harley is a four letter word.
Member Number 433 or there abouts...original old timer