What Causes Weak Cranking of a Car Starter?

[DamianDella]

Reasons for weak cranking of a car starter: 1. Power cable failure; 2. Dead battery; 3. Short circuit or open circuit in the solenoid holding coil; 4. Poor contact at the starter switch terminals; 5. Excessive wear of starter brushes or weak brush springs. Diagnosis and troubleshooting for weak starter cranking: 1. Check the battery capacity and the connection of power cables; 2. If the battery capacity is sufficient and the wiring connections are good, use a metal bar to bridge the two main terminals of the starter solenoid. If cranking becomes strong after bridging, it indicates poor contact between the main terminals and the contact disc inside the solenoid. If cranking remains weak, the motor may be faulty or have poor grounding, requiring further disassembly and inspection; 3. If there is a continuous clicking sound after turning on the starter switch and bridging the solenoid's two main terminals results in normal starter operation, it suggests a short circuit or open circuit in the solenoid holding coil.