a little help with what is probably a easy fix--- FIXED THANKS

Well... nobody answered since I first read this so...

If I got this right, you're asking about how to find out why one transformer is running both trains on 2 separate loops? I really don't even know what you're asking! (I'm slow lately)

You may have something bridging the separate loops at the rails? It is hard to help without much more info. Are either trains pulling lighted pass cars?

Does your track power also power your switch motors?

You just want some guesses on where to start to look for the connection or shorting point?

Troubleshooting needs to be methodical to zero in on the exact problem. Obviously you could start with one transformer unplugged and see where the power is jumping to the other loop. If you don't have a meter handy you could use a lighted car and see where it loses power or where it gets power that it shouldn't.

Have you made changes recently that could be the source of this?

I second the above troubleshooting to determine the cause and would add that one mustunplug  the Z-1000 to properly reset the breaker. The method is in the instructions. Flipping the rocker and leaving it plugged in does not properly reset the breaker.

Now, find what changed on the tracks or wiring...

ENGINEER-JOE and MOONMAN.  Thanks for your advice, I took all the advice and located the problem and it was ME

The problem, when adding a terminal strip for some accessories, I connected 3 strips together, not being an expert (or very smart)  did not check to see if the original strip(s) was connected to a transformer, it was. So 3 strips were spliced together and connecting wires to 2 different transformers, don't have a clue as to why the problem did not occur before, doesn't matter all is well today.

Why did it take so long to fix? It is 100+ degrees these days in the Dallas area and my toys are in the garage.

Thanks 

Brent

Good to hear that you have it resolved - by the way - thanks for posting the issue and the solution - it may help others - a good contribution to the forum - don't fret timeframes - we all move on our own good time