I'm not sure if it is a resistor or some other electrical component, but the factory refers to it as a "Jumper Harness". It plugs directly into the potentiometer and then the regular wiring harness plugs into it. It just looks like 2" of wire with a plug on each end. That is what you need to make the new setup work with a 1400 or 1600 series machine. It should have come with the linkage kit (434092A1E) but if it didn't, I think you can order it as 87412210 for about $14.86. Mike