Blower motor circuit tracing using wiring-diagram voltage checks Learn how to use wiring diagrams to troubleshoot blower motor failures with step by step guidance for tracing power flow, checking voltage, testing motor windings, and diagnosing relay and safety switch faults. This practical guide covers wiring diagram reading, circuit tracing, multimeter voltage checks, continuity testing, insulation resistance tips, and how to interpret schematic symbols so HVAC technicians and homeowners can is