Initial Inspection and Diagnostic Overview

PERFORM BEFORE BEGINNING SYSTEM DIAGNOSIS
1. Check for a broken (or partially broken) wire inside of the insulation which could cause system failure 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).
2. Check for proper installation of aftermarket electronic equipment which may affect the integrity of other systems. (See General Troubleshooting Procedures.) Diagnostic Aids