2026 NOCTI Collision Repair and Refinishing Practice Test – Complete Exam Prep

De-energizing the system by disconnecting the battery lowers the risk of electrical shock during repairs. When the battery is removed, there’s no power path through the vehicle’s circuits, so you’re much less likely to receive a shock and there’s less chance of arcing or accidental activation of components while you work. The best practice is to disconnect the negative (ground) cable first, then the positive, and reconnect in the reverse order after the work is complete. Keeping the battery connected leaves the system energized, and the other options do not remove power from the electrical system.