Phil,
QUOTE (Phil Newman @ 26 Nov 2015, 17:35)
<{POST_SNAPBACK}>Hi Graham, I thought there must be a solution! Your right these crossovers come with four wires already attached one on each of the frogs and one on each of the outer rails. What I need to know is how to wire them for DCC so I don't have polarity issues. Thanks for your response, and if you have the answer please let me know.
Best Regards
Phil
RFS and dwb have provided the correct answer.
The only thing I would add is that to avoid all possible shorting issues, you may want to fit isolating fishplates to every rail end.
Without knowing the context of the layout where these units are to be laid, this is the safest approach, although depending on the feeds from neighbouring track, you may not need to fit insulating joints to every rail.
Personally, I would isolate the whole thing and provide power ONLY through the switches - this is what I have done on the two slips on the entrance to Ashprington Road: