Reverse loop shorting on tail end of HST

[peter_stokes]

I'm running DCC - I just purchased & revcieved the Net Rail NMT - runs really well except that I have a reversing section with a DCC module to change the polarity.
The power car enters the rev. loop ok, but I am getting a short when the second power unit reaches the start of the rev section.
This seems weard as the polarity of the two sections should be the same because the powerr car is already in the loop.
Can anyone advise as to why this might be happening? 

[Flashbang]

Hi

This is a DCC question and needs moving - Admin please.

Is your reverse loop longer than the longest complete train to travel over the loop section?  i.e. the entrance and exit pairs of IRJs need to be a distance apart to allow the whole train to sit inside them onto the loop - loco, all carriages or wagons or any DMU/EMUs.