This module teaches apprentices how to systematically diagnose and resolve electrical faults in residential systems. Working through a structured eight-step workflow — from verifying the complaint through confirming the repair — apprentices develop the skills to identify failure types, trace faults through source, path, load, and control, and apply targeted diagnostic playbooks to the most common real-world scenarios. The focus throughout is on methodical, safe troubleshooting that gets it right, not just fast.