Motor or compressor reads open when hot: internal thermal protector tripped, not (yet) a dead winding

Many small motors and hermetic compressors have a thermal protector built into the windings that opens when the motor overheats and closes again on its own when it cools. Measured hot, the motor can look like it has an open winding. Before condemning it, let it cool fully and retest. If it then runs, the real job is to find why it overheated: low voltage, a failed capacitor, a seized bearing or blocked pump, or poor airflow over a condenser. Compressor sealed-system causes go to an EPA 608 technician.

Cross-checked ~45 min moderateBrands: All

Before you start

Unplug or lock out before measuring resistance; discharge any capacitor first
Hot compressor shells and motor housings can burn; let them cool
Never bypass or jump out a thermal protector
Sealed-system diagnosis (charge, restriction, pressures) is blocked: refer to an EPA 608 technician

Diagnostic steps

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