RayRodany ideas will be greatly appreciated.
First there should be two sets of inslated joiners. One on each end of the section that loops back on itself. That makes the wiring in the loop independent from the main. Without the reverser unit connected this track should be electrically dead. Could not tell from what you wrote if this is already done or not.
Second the independent "loop" section has to be big enough to fit a whole locomotive (or preferably a whole train into) Otherwise the rear is telling the reverser the opposite of what the front is telling it.
Third the AD520 needs the yellow wires going to that independent section of track, the red wires go to power. Polarity is not important as it will flip to match. That is its purpose.
You can also purchase a Digititrax PM42. I really think you should invest in power management.
See this page for an example of wiring a wye with an autoreverser: http://www.dccwiki.com/Reverse_Sections#Application_Example_2:_reversing_triangle Seems the new software that powers this forum has a lot of issues, inserting a link being one of them...
Your first mistake was purchasing the MRC unit. A better purchase would have been the Digitrax AR1.
But the auto-reverse unit is probably not the problem. You need to completely isolate the reversing section of track. To completely isolate the reversing section, you need to have the proper number of rail gaps, and the gaps need to be properly placed. You might also have wired the reversing section improperly. Tell us how you gapped and wired it.
Do you really have a wye? Or is it just a standard turnout that folds the main line track back onto itself?
Also, is it a simple loop or are there other spurs or sidings running off the reversing section?
If it is a true wye, the wiring and gapping may be different than another type of reversing section or reverse loop.
Tell us more about the track configuration or post a drawing of the affected portion of your layout.
Rich
Alton Junction
RayRod,
Your reversing section should be wired like this, with the MRC:
http://www.modelrectifier.com/resources/RAILROAD/AD520.pdf
Frank
Make sure the right or left brach of your turnout is insulated and and the straight section of your turnout too. You should count 4 insulated rail joiners. Your wired auto reverse section should be like an upright j. Your auto reverse section wiring should be completely seperated from the main line and a leg of you turnout again counting 4 insulated rail joiners.
I have is what i believe is considered to be a wye. 16 foot stretch of track that winds back onto the mail line but in a reverse fashion. i purchased the auto reverse loop MRC AD520 and still receive shorts. this happens as soon as it crosses the insulated joiners. the rails are wired in rail red, out black , the area affected is spun from the wiring scheme and is wired reverse within the loop to match the main line.
any ideas will be greatly appreciated.