Bachmann G scale Heisler circuit question

[AndyS]

Thanks to those who replied to my previous question.  After further investigation and tinkering, I now have power to both trucks, but only when I attach wires to the front truck.  Attaching wires to the rear truck will not power either truck.  I can cause a short if I attach the + & - wires to both of the wheels on the same side of the frame.  I am obviously getting power through the contacts, but not to general circuit to power both motors.  Any further thoughts?  Do you think Bachmann would repair this unit?  This unit is very detailed and painted.  I would not want Bachmann to replace the engine.  I have heard they keep that as an option.  Any additional help is appreciated.