I am having problems with a bachman 45 ton locomotive . It ran fine for a little over a  year and then I started having problems with  one of the trucks  . the engine would run fine  running foward, but when you reverse it  one of the trucks would  run  for a couple of inches and then quit running .and would just drag.The other truck however would still be running .
I am not an electrical genious, and I have heard of the problems with the  tension springs  on the electrical pickups . I have pushed on the sides or rocked the bad truck and it  started running again.
I have checked all the wiring and everything seems to be ok,  I have also noticed that when the engine is running foward the rear headlight flickers
  Any Ideas anyone??  Thanks