Systems and methods to couple electrical contacts of a header of a medical device to respective feedthrough pins of a connector block of a medical device housing using a preformed wire are disclosed. The preformed wire can include a proximate portion comprising a number of turns shaped to engage a feedthrough pin. The number of turns of the preformed wire, once engaged with the feedthrough pin, can physically separate a major portion of the preformed wire from the connector block and the housing. The major portion of the preformed wire can be shaped to route a distal portion of the preformed wire to a first electrical contact of the header when the proximate portion of the preformed wire engages the feedthrough pin.