A Preliminary Information

Most lighting problems are caused by the following items:
- Loose connectors
- Open or shorted wiring
- Burned-out bulbs
- Bad switches
- Inadequate grounds
- Open fuses

Many of these problems are repaired by replacing a part that requires a special procedure, such as a lens and housing sealed together. For these repairs, follow the instructions normally included in the replacement parts package.

When removing a component that requires special sealing items, such as sealing washers, be sure to reinstall those items when replacing the component. If any body sealing items, such as grommets, are disturbed, be sure to repair them so that the passenger compartment remains properly sealed.

Use the following general guidelines in order to diagnose a lighting system problem:
- Verify the owner's complaint.
- Attempt to operate the other systems that are powered through the same fuse.
If the other systems powered through the same fuse are inoperative, replace the fuse. Refer to Headlights Schematics (Domestic) or Headlights Schematics (Export) or Headlights Schematics (Export w/DRL) for fuse applications.
- Check for aftermarket (non-OEM) equipment. If add-on accessories are discovered, disconnect the system in order to make certain that the add-on is not the cause of the problem.
- Check all connectors and related wiring to the suspect electrical component:
- Poor mating of connector halves
- Terminals not fully seated in the connector body (backed out)
- Dirt or corrosion on the connector terminals.
The terminals must be clean and free of any foreign material which could interfere with proper terminal contact.
- Check related ground eyelets for a clean and tight connection.

If the above general guidelines fail to achieve a satisfactory conclusion, refer to the following schematics for further electrical wiring and diagnostic information:
- Headlights Schematics (Domestic)
- Headlights Schematics (Export)
- Headlights Schematics (Export w/DRL)