1. PHASE WIRES (3 thick wires): Phase A/B/C carry the motor power from the controller to the windings. Match them to the controller's phase outputs. 2. HALL WIRES (5 thin wires): Hall A/B/C report the rotor's position so the controller knows when to fire; Hall 5V powers the sensors; Hall GND is their ground. 3. Phase wires usually end in bullet connectors, hall wires in one small 5-pin block — different connector types, but match by FUNCTION anyway. 4. Wire colors are not standard across brands. Your motor's blue might be the controller's green. Confirm every wire against each unit's label — never match by color alone. 5. Motor stutters or spins backwards after a swap? The hall/phase pairing is wrong — re-check it before you ride. 6. If your controller has a self-learn wire, use it once after a motor swap — it figures out the pairing for you. Got a wiring question? Swing by the shop and we'll sort it out together.