Unless of course you put a simple isolating section in at the end of the platform where the loco is, the coaches can still pick up power then, as mine do. However, for me it was the quality of the coach that made me buy my Pullmans and not the coach lighting which is pointless unless operating in the dark, at which point I trip over !
Now if only they wold run properly in a rake of more than 8!
Pieman