What Causes Weak Engine Cranking but Still Able to Start?

[LeGia]

Weak engine cranking during startup can be attributed to the following malfunctions: 1. Battery: Due to long-term undercharging, lack of electrolyte, or overcharging, the battery's storage capacity deteriorates. This results in weak starter motor performance after each engine shutdown and during subsequent startups. 2. Starter Motor: Prolonged usage leads to excessive wear of internal copper sleeves, rotor scraping, or contact point erosion in the engagement switch, causing weak cranking power. 3. Alternator: Issues like worn voltage regulators or carbon brushes cause the alternator to produce either excessive or insufficient power output. Excessive charging can lead to battery overheating or electrolyte depletion over time, damaging the battery and causing weak cranking. Insufficient charging keeps the battery in a chronically undercharged state, resulting in weak starter motor performance during startups.