Automotive Service Excellence (ASE) A6 Electrical/Electronic SystemsStarting System Diagnosis and RepairEasy
During a starting circuit inspection, a technician notices significant corrosion around the battery terminals and cable ends. Which of the following is the most likely consequence of this condition?
- AReduced resistance in the starting circuit.
- BIncreased resistance, leading to slow cranking or a no-start condition.
- CPremature failure of the vehicle's electronic control unit (ECU).
- DIncreased voltage output from the alternator.
Show answer & explanationAnswer & explanation
Correct answer: B. Increased resistance, leading to slow cranking or a no-start condition.
Corrosion on battery terminals and cable ends acts as an electrical insulator, increasing resistance in the circuit. This increased resistance restricts current flow to the starter motor, leading to slow cranking or a complete no-start condition.
Why the other options are wrong
- A. Corrosion *increases* resistance, it does not reduce it.
- C. While severe electrical issues can sometimes affect ECUs, corrosion primarily impacts the high-current starting circuit and is not a direct cause of ECU failure.
- D. Corrosion in the starting circuit would not directly increase alternator voltage output; it primarily affects current flow.
Battery Terminal Corrosion Effects
Corrosion on battery terminals and cable ends creates high resistance in the electrical circuit, impeding current flow.
- Acts as an electrical insulator.
- Increases resistance in the starting circuit.
- Leads to symptoms like slow cranking or a no-start condition.
Memory trick: Corrosion's barrier makes current tarrier.