Electrical System Troubleshooting Technique

The following five-step troubleshooting procedure is recommended.

1. Verify the Problem

Check the operation of the circuit to be sure you understand the problem. Do not begin disassembly or testing until you have narrowed down the possible causes.

2. Analyze the Circuit Diagram (schematic)

Check circuits that share the wiring with the problem circuit. The names of shared circuits are often given on each Circuit Diagram to aid troubleshooting. Shared power and ground circuits can be found in the Power and Ground Distribution. Power and Ground Distribution Try to operate the shared circuits. If these circuits work, then the shared wiring is OK. The cause must be within the wiring used only by the problem circuit. If several circuits fail at the same time, chances are the power (fuse) or ground circuit is faulty.

3. Find the Cause

Narrow down the possible causes. Before you replace a component, check power, signal, and ground wires at the component harness connector.

4. Repair the Problem

Once the specific problem is identified, make the repair. Be sure to use the correct tools and safe procedures.

5. Check the Repair

Check the operation of the repaired circuit in all modes to make sure you fixed the entire problem. If the problem was a blown fuse, be sure to test all of the circuits on that fuse. Make sure no new problems are present.