What is the correct sequence for disconnecting jump-start cables after the donor engine has started?

• A. Disconnect in reverse order of connection: first remove negative from chassis ground, then negative from donor, then positive from donor, then positive from battery.
• B. Disconnect positive from battery first.
• C. Remove all cables while engine is running.
• D. Remove negative from donor first.

Answer: (A)

The main idea is to disconnect jump-start cables in the reverse order you connected them, which minimizes sparks and protects against short circuits or arcing near the battery.

After the donor engine is running, start by removing the negative clamp from the chassis ground of the vehicle that needed the jump. Next, take off the negative clamp from the donor battery, then remove the positive clamp from the donor battery, and finally remove the positive clamp from the dead battery. This sequence keeps the live positive connections away from ground while you break the circuit, reducing the chance of a spark reaching the battery.

Avoid removing the positive connection first or removing all cables while the engine is running, as those actions increase the risk of sparks or accidental shorts.