Five-Step Troubleshooting

The following five-step troubleshooting procedure is recommended:

1. Verify the Problem
Check the problem circuit's operation to be sure you understand what's wrong. Do not begin disassembly or testing until you have narrowed down the possible causes.

2. Analyze the Circuit Schematic
Analyze the schematic. Read the Circuit Operation text if you do not understand how the circuit should work. Check circuits that share the wiring with the problem circuit. The names of circuits that share the same fuse, ground, switch, etc., are included on each electrical schematic. Shared circuits are also shown on Power Distribution, Ground Distribution, Dash Fuse Box, and Lighting Switch Detail. 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
- use the troubleshooting hints
- make the necessary measurements as given in the troubleshooting procedures
- 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 proper tools and always observe safe procedures.

5. Check the Repair
Check the repaired circuit's operation in all modes to make sure that you've fixed the entire problem. If the problem was a blown fuse, test all circuits on that fuse. Make sure that no new problems turn up.