To provide a motor protector which is adapted to protect a motor of engine cooling system for a vehicle from locked rotor status.

A self-hold motor protector (10) has an open metallic housing (12) in which a thermostatic disc (14) carrying a movable electrical contact (18) is cantilever mounted. A heater seat plate (20) is mounted in the housing in electrical and thermal relationship therewith. The heater seat plate has a seating recess (20a) in which a positive temperature coefficient resistor heating element (22) is received with one contact surface in electrical and thermal engagement with the heater seat plate. A terminal plate (26) mounts a stationary electrical contact (28) and is received over the opening of the housing but electrically isolated therefrom by a gasket (24). An electrically conductive spring (30) extends between the terminal plate and a second contact surface of the heating element.