What are the causes of weak starter operation?
2 Answers
Causes of weak starter operation: 1. Power wire failure. 2. Dead battery. 3. Short circuit in the solenoid holding coil. 4. Poor contact of starter switch contacts. 5. Excessive wear of starter brushes or weak brush springs. Diagnostic methods for slow and weak starter rotation: 1. Use a conductor to bridge the two terminals on the starter switch. If the starter speed increases significantly, it indicates poor contact of the starter switch contacts, leading to increased resistance. If the starter speed remains unchanged, check whether the battery is fully charged, whether the brushes are excessively worn, or whether the brush springs are too weak. 2. Internal short circuits in the starter's armature coil or field coil can also cause weak starter operation. Carefully inspect the starter circuit wires and connections. Poor wires, loose connections, or corroded terminals can generate heat due to increased resistance. 3. Mechanical faults inside the starter can also affect its normal operation. If the power supply, starter circuit, and starter switch are all in good condition, check whether the starter bearings are too tight or whether the armature shaft is bent, causing friction between the armature and the magnetic poles.
That day my car's starter was running weakly, making a buzzing sound when turning the key but the car wouldn't start. The most common reason is a weak battery, especially an old battery that's been used for several years, as insufficient charge leads to low voltage. Also, check the wire connection points—if they're rusty or loose, the current can't pass through properly, causing this issue. In cold winter weather, battery performance worsens, requiring preheating or charging. Internal starter issues like worn brushes or stuck gears should also be checked, otherwise it may lead to complete failure to start. I recommend going to a professional shop early to test the voltage and clean the connections, rather than waiting for a roadside breakdown. Regular maintenance can save hassle and money, such as testing battery health every six months.
