I am hoping that someone may be able to offer me a solution to my problem. I am building a new DCC based layout, built with C track and including some 30 turnouts. I have used the 74462 decoders and 74491 motors in the turnouts. I am using a YaMoRC YD7010 DCC Controller, although I also have a Roco Z21 (Black) controller, and the issue remains with either. My layout is L speed 4 x1.2 m and 3 x 2 m.

My issue is intermittent problems of the turnouts not switching when commanded. This is not restricted to specific turnouts but across the whole layout. Any one turnout will be working one moment and then not the next. However, if I test a non-working turnout connected to the programming track it will work perfectly, switching on command, and the CV values are all correct. I have tried setting CV8=8, as suggested in some other thread posts, but that has not worked. If I then replace the turnout back onto the main track it will either still not work, or work once and then fail. I don't understand why a turnout will work on the programming track, and then not work on the main track.

I am currently laying down the track and wiring it up, so at present there are no other sensors or accessories connected to the layout. I have used 24/0.2 wire for the track power feed, and have between 16.5 and 17.2 voltage on track and at the turnouts when I test with my multimeter. I have power feeds to the track piece adjacent to the turnouts.

My layout building at a standstill till I can resolve the issue and I am not sure the best way to move forward. I understand from other posts on this and other forums that others have suffered from similar problems and thus any advice or suggestions as to how to resolve the problem would be most welcome.

Many thanks

Hi Peder

Thanks for your post

yes locos run OK.

Alex

Hi Jean
Many thanks for your post.
Just to be clear in my mind, are you saying that the 74491 and 74492 motors were the ones giving reliability issues, or that the 74491 and 74492 motors are the motors that have resolved the issues. It's just that my motors are all 74491's. All of my turnout decoders are the 74462.

Many thanks

Alex

Hi
That was one of my thoughts, so I switched out the YD7010 Controller for the Z21 controller and got the same results, so I dismissed that. I also suspected that it could be my wiring so ran some wiring straight from the controller to one short section of track, with two sets of turnouts attached. The turnout nearest the power supply didnt work, as usual, but the second turnout worked perfectly. Both worked perfectly on the programming track.

Dear Alex -

Could it be track geometry? I had a problem once with a very simple, C-track layout (i.e., 3 rail) consisting of a straight section of track with a reversing loop at each end (connected with a turnout; a dumbell-shape). It was fed with power and control signals from a MS2+gleisbox at a single connection point.

I found that unless I put isolators (74030s, the red things) in the reversing loops somewhere, I could not run locos properly (they would stutter and run slowly). My guess was that there was interference with the control signals going both ways round the reversing loop. If you have a similar geometry (or one that leads to control signal interference), that could be the problem actuating your turnouts on the layout, as opposed to on the programming track.

(I would like to know why isolators are required for this track geometry, but that probably is a separate forum topic.)

Osoraku

Connect the non-functioning switches to the programming track and ensure they are working properly that way. Then swap the power to the programming track with the regular power output and see if they continue to operate properly. That should indicate whether you have a wring problem or a controller problem.

Thanks, I will try that tomorrow morning

Alex