Troubleshooting Hints

Perform before beginning System Diagnosis
1. Check that G400 is clean and tight.
2. Check PWR ACCY Fuse and Courtesy Fuse for open. If either fuse is open, check for short to ground through CKTs 640 and/or 40.
3. For vehicles with Manual Transmissions, the "BRAKE" Indicator receives a ground through the Park Brake Switch. Applying the Park Brake and observing the "BRAKE" Indicator can be used as a quick check of the ground CKT below S228.
^ 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 to "General Troubleshooting Procedure"). Diagnostic Aids
^ Refer to System Diagnosis. System Diagnosis