Getting a short when attaching new bus wires to existing layout

Did your redesign of the track plan include adding a wye or return loop?  Did your new design have a short prior to adding the bus? 

No, no wyes or return loops. I had a small 2 track yard that I repositioned. Kind of difficult to explain. Probably best to draw track plan explaining what I did. I think I may disconnect every feeder and start over at this point.

No need to disconnect all.  Go halfway and break it there.  If you still have the short go back another 1/4 and break it there.  At some point it should be good so you can narrow it down and just fix the misswire.  Then start adding the breaks back in just in case you have another wiring mistake.

Thanks.  I will draw up a simple track plan of what I had and what I did to try to help with the confusion.  Greatly appreciate your help.  It's been down for almost 2 months and I an going through some major withdrawal! Lol! Getting very disappointing going down to the layout and not being able to run trains. Attached video is from when they were running.

I suggest you show us both the old track plan that worked as well as the new one with the short.

Hopefully this helps. Dotted lines are where old plan was. Only added a few feet of track and just rearranged turnouts and took out old loops.

The track changes do not appear to be the source of the problem. What happens if you remove the new feeders. Do you have any other feeders still in place to run trains on part of the layout?

I put new bus wires from the CS going left and dead ended where suitcase connectors would go to continue over bridges with no feeders attached. When I turn the system on it doesn't short. I attached 2 feeders (one to red bus and one to black), once turned on it shorts. I tested power from CS with a RRAMP meter and shows 14.1-14.2 volts. Pics attached. The picture where you see the road going down hill is where I did the majority of the changes.

When you remove those two new feeders, can you run trains anywhere else on the layout?

Unfortunately no. I was thinking I haven't attached enough feeders maybe.

I'm in over my head here being a conventional power 3-railer. Still, my approach would be to get SOMETHING working. I have a temporary circle of track I can put a single loco on with power and test run. Once I know it's good, I can hook up to part of the layout using that loco. I have switches on the control panel to kill sections of track. I kill everything but one, and test it. If it works, then I add one section at a time and test run until it doesn't work anymore. That tells me where the problem is.

I have had shorts in a track switches twice: once from foreign matter, once from part of the switch touching another part that it shouldn't. I have had shorts from wires touching under the layout that didn't before. I've also had dead places from solder joints that failed.

Uninsulated frogs in new switches can be a short in 2-rail practice, based on my decades-old HO experience.

One of those cars parked in the yard could be off the track on a switch and create a short. Maybe start by making sure all cars on the track roll freely and are clear of track switches?

It can be some work to track things down, and you may need to cut some gaps and put some spst switches in your panel, but in the end, this isn't that complicated, and you can do this. It probably won't be the last time something fails and things stop working.

I hooked up a separate piece of track to my command station and was able to start my locos. I believe I need to attach more feeders and may be good. Fingers crossed! Thanks for your input.

@Ian Pinckney posted:

I hooked up a separate piece of track to my command station and was able to start my locos. I believe I need to attach more feeders and may be good. Fingers crossed! Thanks for your input.

If you actually have a short circuit, adding more wires won't fix it.

I had a short on the last layout I built and I couldn’t find it.  So I had to disconnect everything from the terminal block and add each drop back one by one until I found the drop that was causing the short.  It’s no easy fix.

I didn't add more feeders . I disconnected all the ones I had attached and attached only 2 new feeders to the new bus wires i installed on about 15-20 feet of new bus wires. I plan on attaching the rest of the feeders tomorrow and hopefully that will do it. Not out of the woods yet but was a good sign I was able to hook up a short section of track and able to operate the locos. Feeling better now than I was a few days ago especially after hearing them fire up and able to move them. About the only thing I can think of now is the lack of feeders.

More places to look for a short:

1. New bus wires backwards polarity from original bus wires.

2. New feeders attached to wrong rails/busses.

3. Old disconnected feeders hanging down under layout touching wrong old bus.

4. Old disconnected feeders hanging down under layout touching each other.

Well I just attached about 30 new feeders to new bus lines red to red black to black and still getting short on command station.  Will keep working on it. Still have several to go with several feeders hanging down under layout but nothing touching bus lines or feeders that I can see.

In my opinion, adding new feeders has complicated the situation instead of simplifying it, and made it harder to find the short than easier. At this point, I suggest disconnecting the new busses completely, and trying to run on the original layout trackage.

Correction, I attached the existing feeders to the new buses. I just detached the black wire from the command station and left the red wire in from power supply and no short. Really wish I had someone who is a dcc guru near me lol! Thanks for the help.

I would disconnect the 30 feeders back to only two where you have no short and then add the feeders one at a time and tested after adding each one. That should help pinpoint where your short is.

That is my new plan thanks. I just disconnected the CS and attached power to older part of layout that has a 25 foot run with passing siding and locos ran fine with no short. Believe I am narrowing it down. Definitely has to be something with the feeders I have attached.  Can only hope! I know one thing, once I get this back together properly, I am not touching it again!

There's only a few possibilities. Most likely, you have a left rail feeder connected to the right rail bus and visa versa.  One crossed connection will short the whole thing out.
Beyond that, make sure that insulation gaps are present around switch frogs so that power isnt jumping from one rail to another within a switch.

Understood thank you. My turnouts are Atlas O Supreme and don't need insulated joiners. I will be tracing the feeders for the next few days and hopefully get it figured out. 

So, if you have things working on the old layout, I suggest adding back ONE wire at a time, and test running after EACH new wire is added.

Woo-hoo hoooooooo!!! Back up and running! Found 2 feeders connected wrong. Thank you everyone for your input, help and especially time in helping me figure this out. Hope everyone is doing well.

Congratulations!

Thank you!! Now to clean the track and wheels and test, test and more testing lol!

@Bill Sherry posted:

No need to disconnect all.  Go halfway and break it there.  If you still have the short go back another 1/4 and break it there.  At some point it should be good so you can narrow it down and just fix the misswire.  Then start adding the breaks back in just in case you have another wiring mistake.

Glad you found it but it is worth emphasizing this methodical approach is always a good start.

Most definitely.  I am glad I decided to take one last look at the wiring.  It also made me aware of other spots that need attention to get the trains running better.