Here are a few reasons why a car may have 10.5 volts but still fail to start:
1. Weak or Dead Battery: Even though the battery shows 10.5 volts, it might be too weak to provide the high current needed by the starter motor. As batteries age, their internal resistance increases, making it harder for them to deliver high current.
2. Bad Starter Motor: If the starter motor is faulty, it may require more power than the battery can provide, even with 10.5 volts. A faulty starter can draw excessive current or have internal mechanical issues, preventing the engine from cranking.
3. Dirty or Corroded Connections: Poor electrical connections between the battery, starter motor, and other electrical components can lead to voltage drops and reduced power flow. Corroded or loose terminal connections can hinder the battery from supplying enough power to the starter.
4. Electrical Issues: There might be other electrical problems in the vehicle's wiring, ignition system, or electrical accessories draining the battery or preventing the starter from receiving power.
To determine the exact cause, it is advisable to have the battery tested using a battery load tester to assess its ability to deliver high cranking amps. Additionally, inspecting the starter motor, electrical connections, and other relevant components is essential to identify any potential issues. A qualified mechanic can diagnose the problem accurately and perform the necessary repairs or replacements.
