U.S. Motors pool pump controller shows E05 immediately when START is pressed; motor does not attempt to turn.

Safety first: Disconnect power at the breaker and confirm with a meter before opening the motor wiring compartment.

• Inspect motor connections: Remove the motor terminal cover and verify all motor leads are securely connected according to the wiring diagram. Tighten any loose terminals.
• Check continuity: With the motor leads disconnected and power off, use an ohmmeter to measure resistance between motor windings (e.g., between common, start, and run terminals on single-phase motors). Infinite resistance indicates an open winding or open thermal protector.
• Check motor cable: If the pump uses a separate drive module and motor cable, inspect the cable for damage and test continuity end-to-end on each conductor.
• Allow motor to cool: If the motor was overheated, the internal thermal protector may be open. Allow several hours to cool and retest. If it never resets, the protector or winding is failed.
• Replace motor if open: If any winding is open or the thermal protector does not reset, replace the U.S. Motors pool pump motor assembly.