EXPLANATION OF TROUBLESHOOTING PROCEDURES
Troubleshooting procedures are defined as follows:
1. SYMPTOM: Indicates fault that has occurred in system/equipment.
2. MALFUNCTION: Indicates possible malfunction that may cause the symptom.
3. CORRECTIVE ACTION: Indicates test or inspection to be performed to isolate problem and correct cause
for the malfunction.
ELECTRICAL TROUBLESHOOTING-GENERAL INFORMATION
Refer to Electrical General Maintenance Instructions (Volume 2, WP 0280) for instructions
the symptoms and conditions and use common sense and logic to determine the most likely
cause for the problem, the easier it will be to troubleshoot.
1. Isolate to the subsystem level (in cases where more than one subsystem is involved); next isolate the
problem to a single circuit within the subsystem; then, isolate the problem to the faulty component using the
2. Frayed, broken, loose, or corroded wiring is a common source of problems in any electrical circuit. Always
make visual inspection before starting detailed troubleshooting. Pay particular attention to contacts to ground
and components with case grounds.
3. Most of checks made are voltage checks. Pay particular attention to voltage being checked in procedures.
This equipment is a 24 volt system. Instructions prior to the step instruct to disconnect at test point from the
potential malfunctioning component. Once the check has been made, either repair the component or go to
the referenced step. If going to another step, reconnect connection or do as otherwise instructed, such as
install jumper wires using jumper wire kit. When ready to make the prescribed check, apply power to the
circuit (if required). A helper may be required if the switch or power source is out of reach. Release the power
function prior to going on, to avoid damage to equipment.
4. Refer to the following simplified electrical schematics when performing electrical troubleshooting.