What are the symptoms of a bad car carbon brush?

[StEthan]

It will cause the motor of the starter to fail to rotate or lack sufficient power. The symptoms include hearing a slow and weak starting sound or only the sound of the pinion gear operating mechanism working. The engine will have difficulty starting or may even fail to start. Below is more information about starter carbon brushes: 1. Introduction: Carbon brushes are mainly made of graphite containing copper and silver, used to transfer electrical energy between the stationary and rotating parts of the motor. The carbon brushes in starters are block-shaped and are pressed against the commutator shaft of the starter by spring preload. 2. Service life: Starters are only used during engine starting. Generally, the carbon brushes in vehicle starters can last over ten years without issues. However, other factors causing starting difficulties that require multiple attempts can lead to accelerated wear of the carbon brushes, resulting in a shorter lifespan.