  We study transport in a voltage biased superconductor-normal-superconductor
(SNS) junction made of semiconducting nanowires with strong spin-orbit
coupling, as it transitions into a topological superconducting phase for
increasing Zeeman field. Despite the absence of a fractional steady-state ac
Josephson current in the topological phase, the dissipative multiple Andreev
reflection (MAR) current I_dc at different junction transparencies is
particularly revealing. It exhibits unique features related to topology, such
as the gap inversion, the formation of Majorana bound states, and
fermion-parity conservation. Moreover, the critical current I_c, which
remarkably does not vanish at the critical point where the system becomes
gapless, provides direct evidence of the topological transition.
