Initial Inspection and Diagnostic Overview
PERFORM BEFORE BEGINNING SYSTEM DIAGNOSIS:^ Check for a broken (or partially broken) wire inside of the insulation which could cause system malfunction but prove "GOOD" in a Continuity/voltage check with a system disconnected. These circuits may be intermittent or resistive when loaded, and if possible, should be checked by monitoring for a voltage drop with the system operational (under load).
^ Check for proper installation of aftermarket electronic equipment which may affect the integrity of other systems refer Diagnostic Aids. Diagnostic Aids
^ Refer to System Diagnosis. System Diagnosis