What is the most economical way to run multiple trains on n scale layout?

I have an older power routing switch on my layout.  It is the return switch for a second track off the main route.  The engine will go straight through the switch, but when I turn the switch to the return track the power cuts out.  It only seems to power the track in the one direction. 

What is the best way to extend the connections from switches to the controller and power pack?  I need more distance than the included wires allow.