Irish Rose,
Yes, Jon is right to a point, they are a PITA to rewire, but not that hard really.
It took me about three months and three or four rewirings before I actually had a mental grasp on this 4 wires to 3 connectors design.
The plug you show disassembled is only half of the circuit. So you are not seeing the whole picture. I have several wiring diagrams that I've collected printed out, but no URL for me to refer you to. They are on my dead PC.
OK, I found one of them.
http://www.treadleon.net/sewingmachi...ng/wiring.html
If your machine was running correctly before the wire shorted out, just rewire it as it was.
I hate working on 110/120 V electric stuff so if I can do it, so can you.
~Or~
Go to Sew-Classic and buy a replacement set and send me the burned out one. I can use the parts.
Joe