What are the symptoms of a bad motor carbon brush?

[SanJoseph]

When the motor carbon brush is damaged, it can cause the starter motor to fail to rotate or rotate weakly. Here is some related information: 1. Motor carbon brush: The motor carbon brush is a general term for the carbon brushes of motors and generators. The motor carbon brush looks somewhat like an eraser strip for pencils, with a wire lead at the top, and comes in various sizes. 2. Function: In a motor, its role is to change the direction of current, divided into DC motors and AC motors. In DC motors, it changes the conductive coil of the rotor, thereby altering the rotor's magnetic poles and subsequently the motor's movement. The carbon brush is used on the motor's commutator or slip ring as a sliding contact body for exporting and importing current. It has good conductivity, thermal conductivity, and lubrication properties, along with certain mechanical strength and the ability to handle commutator sparks. Almost all brushed motors use carbon brushes, making them an essential component of brushed motors.