If the starter relay chatters rather than locks in when the start switch is in START position, what does this indicate?

Prepare for your ASA Powerplant Mechanic Exam with interactive flashcards and multiple choice questions. Each question features detailed hints and explanations to ensure you're ready for the test.

Multiple Choice

If the starter relay chatters rather than locks in when the start switch is in START position, what does this indicate?

Explanation:
When you press the start switch, the starter relay should energize and then latch, keeping the starter engaged. If the relay chatters, it means the coil is being energized but not receiving enough current to hold the contacts closed. The holding current is not being met, so the magnetic force drops, the contacts open, and the cycle repeats as the coil re-energizes. The most likely cause is insufficient battery voltage or poor connections in the starter circuit, which prevents enough current from reaching and sustaining the relay coil. Check the battery state of charge and voltage under load, along with cables, clamps, and any parasitic resistance in the wiring. Welding of the relay contacts would typically keep the circuit locked on or prevent it from operating reliably, not cause a rapid on-off chatter. An ignition exciter failure would prevent energizing the relay in the first place rather than causing it to chatter. A generator output short to ground would create a different fault condition, usually with heavy current, protection trips, or other symptoms rather than a repeating lock-unlock action.

When you press the start switch, the starter relay should energize and then latch, keeping the starter engaged. If the relay chatters, it means the coil is being energized but not receiving enough current to hold the contacts closed. The holding current is not being met, so the magnetic force drops, the contacts open, and the cycle repeats as the coil re-energizes. The most likely cause is insufficient battery voltage or poor connections in the starter circuit, which prevents enough current from reaching and sustaining the relay coil. Check the battery state of charge and voltage under load, along with cables, clamps, and any parasitic resistance in the wiring.

Welding of the relay contacts would typically keep the circuit locked on or prevent it from operating reliably, not cause a rapid on-off chatter. An ignition exciter failure would prevent energizing the relay in the first place rather than causing it to chatter. A generator output short to ground would create a different fault condition, usually with heavy current, protection trips, or other symptoms rather than a repeating lock-unlock action.

Subscribe

Get the latest from Examzify

You can unsubscribe at any time. Read our privacy policy