This is an isolated bulk head fitting.  
 
When replacing this connector ensure that the yellow wire with the black
marking goes to the shield and the other wire goes to the center conductor.
 
After installing ensure that the machine will stop when an arc occurs in the
automatic mode. If it does not stop try reversing the polarity (solder the
yellow wire with the black marking to the center conductor and the other
wire should go to the shield).  
 
 
 
ELECTRICAL BOX - VIEW D
SWING-ARM