Wiring Switch Track

[PeteDaFinn]

Just got an N scale Durango set and bought a separate switch track to extend the layout slightly. The wiring diagram shows it should be connected to the controller but there's no place to attach it on this set. The manual switch works ok although the train tends to stall when its set to go through the straight track - is there anyway to wire the switch without buying a new controller? Any reason why the train tends to stop when going through the switch?