I have an autoreversing standalone track about 15 feet long, only one right angle curve.  The set up is comprised of a Bachman HO autoreversing boxed set and some additional autoreversing straight tracks purchased separately.  Even brand new streetcar will fail to make the reversing changeover at the far end of the run - opposite the power track.  This failure to revers occurs not immediately but after five or six down-and-back runs.  The loco will go dark at the end of the run and stay dark. One affected streetcar is brand new, the other only a year old.  Most of the tracks are only one Christmas season old and the others are brand new.  It is difficult to imagine this is a dirty rail or dirty contact wheel problem.

Can the power track be positioned in the middle of the run to cut the effect of voltage drop along the run in half?  Or must the power track stay at one terminus?  Thanks in advance for your help.