TROUBLESHOOTING INTRODUCTION - CONTINUED
EXPLANATION OF TROUBLESHOOTING TABLE COLUMNS
The columns in the tables in each troubleshooting work package are defined as follows:
MALFUNCTION. Indicates fault that has occurred in system/equipment.
TEST OR INSPECTION. Indicates test or inspection to be performed to isolate probable cause for fault symptom.
CORRECTIVE ACTION. Indicates procedure to correct the problem.
ELECTRICAL TROUBLESHOOTING GENERAL INFORMATION
Refer to Electrical General Maintenance Instructions (WP 0021 00) for instructions on using a multimeter
to check for continuity or shorts and to perform voltage checks.
Analyze the symptoms and conditions and determine the most likely cause for the problem, then troubleshoot that cir-
cuit first. The more information you have concerning the problem, the easier it will be to troubleshoot.
Isolate to the subsystem level (in cases in which more than one subsystem is involved); next isolate the problem to a sin-
gle circuit within the subsystem; then, isolate the problem to the faulty component using the Troubleshooting Symptom
Frayed, broken, loose, or corroded wiring is a common source of problems in any electrical circuit. Always perform
visual inspection before starting detailed troubleshooting. Observe contacts to ground in particular. Components with
case grounds are especially troublesome.
When performing continuity checks, ensure the test equipment is isolated from the power source.
Most checks performed are voltage checks. Pay particular attention to voltages being checked in procedures. This equip-
ment is a 24-volt system. Instructions prior to the step instruct to disconnect at test point from the potential malfunction-
ing 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). An assistant may be required if the
switch or power source is out of reach. Release the power function before proceeding to avoid damage to equipment.
END OF WORK PACKAGE