I am planning to set up a Marklin signal and want to check I am wiring it right. I am also wondering if I am right in thinking that I will need the Universal Relay? The plan is that the train will pass a Marklin circuit track. When it does so the signal will go up. Then it will pass the signal, then another Marklin circuit track. At this point the signal will go down. That's it. I would like to verify how I connect the wires for the signal. I think I understand where the yellow wire goes. That's ground. Want to check the rest. There will be no isolator rail involved so I am thinking that the wires from the signal that control that will not be connected? Thanks in advance as usual for any advice.