App note from Precision Microdrives on how to properly connect wires on to vibration motors for reliability. Link here
Vibration motors require electrical power, which must be delivered by wires or PCB tracks to the motor. Precision Microdrives vibrating motors are available in a range of connector forms. From stock, they are available with factory installed leads, terminals, PCB solder pins, or as PCB SMT / SMD options. Solder pins and SMT motors have the advantage of being mounted directly onto the PCB which simplifies the connection process.
hahaha an entire article just saying to heat-shrink your wires or glue them if they might move around a lot. When did common sense die?