DCC Wiring problem

[R300AML]

I am building a Helix (See Helix post) the Layout has two different level tracks above the main base track work, each level is reached by a helix, and both helixes will be on the same track work so locos can run around both levels before returning to their start point.My problem is this: The top track goes around three sides of the layout and returns via a return bend at the end of the run. To save buying a polarity reverser, I ran the track back to the helix point, thereby making two tracks around the top of the layout, one outward bound and then the return track is the inbound. When I tested the track, I had a short circuit, as the inner rail of the outside track was positive, and because the track returns and runs back, the outside rail of the inner track needs to be positive as well,as it is all one piece of track returning on itself, so I changed over the wiring and problem solved ...... or NOT? whilst testing the helix, as I built each layer, I noticed that the outside track worked fine, the loco going forwards, but the inside track, the loco went backwards on the forwards setting, because I connected the helix up to match the wiring of the top track with it's return track. Do I need an auto reverse module ? I have 3 Gaugemaster modules so do I wire one in maybe at the top of the helix, with isolating track joiners to overcome this problem? I am testing the layout with DC, or do decoders in the locos sense a polarity change themselves?

[Nigelcliffe]

Track polarity has no impact on locomotive direction.   Locos go forward (chimney to the front, or no-1 cab to front) regardless of which way round the track wires are connected.   
Set a loco going forwards, then pick it up, turn it round, and put back on the track, it will still go "forwards" (chimney to front).  

 

 

I don't follow your track description, but if it means "the track is just a very squashed circle, up one side of the helix, and back down the other side", then you don't need any reversers.    Or, you don't need them provided there are no turnouts linking the two sides of the squashed circle. 

[R300AML]

Oh Nigel, Sorry mate, I had a bit of brain fade at 7 am this morning- I was testing the track I fitted last night  and I put the loco on the track facing the same way both times so of course it was going backwards! I only had to turn the loco around and I forgot that the loco comes down the inside track and up the outside track so all is well, but thanks for your quick reply, I was about to delete this post, but you've given me some valuable info anyway. Suppose I should be testing with DCC, it may save some confusion in the future but the layout is nowhere near finished, so I thought DC was okay for now. Really do appreciate your support though, cheers for now, Alan