Check the under-dash panel on the driver side first if interior systems stop working, since most low-amperage circuits are grouped there. Use the numbered layout on the cover to match each slot with functions like radio, dashboard lights, and power accessories, typically rated between 7.5A and 20A.
The engine bay power distribution unit near the battery handles high-current lines for ignition, cooling fans, and charging system. Look for larger cartridge-style elements rated 30A to 80A, which protect critical components such as alternator and main power supply.
Link each electrical issue to a specific circuit before removing anything. For example, loss of brake lights usually traces to a 10A position, while power window failure often points to a 20A slot. Always confirm both location and rating to avoid installing the wrong replacement.
Use a puller tool to remove each protective element and inspect the internal metal strip. A visible break or burn mark signals failure. Replace only with the same amperage rating to prevent overheating and wiring damage.
1999 Honda Civic EX Fuse Box Diagram with Locations and Circuit Details
Check both the under-dash panel and the engine bay power unit to locate the correct circuit quickly. The interior section handles low to medium loads, while the compartment near the battery supports high-current systems like ignition and cooling fans.
Use the slot numbering system to match each position with its function. Typical interior assignments include:
- 7.5A for dashboard lighting and control modules
- 10A for brake lights and turn signals
- 15A for audio system and accessory outlets
- 20A for power windows and door locks
In the engine compartment, larger cartridge-style elements protect key systems. These commonly include:
- 40A for radiator fan operation
- 50A for ignition switch supply
- 60A to 80A for main battery and alternator lines
Relays placed near the power distribution unit control switching for headlights, fuel pump, and horn. Swap with a matching relay from a non-critical circuit to confirm faults when no visible damage appears.
Follow a step-by-step check to avoid errors:
- Identify the failed system
- Locate the corresponding slot using the panel chart
- Verify amperage printed on the component
- Inspect the internal metal strip for breaks
- Install a replacement with the same rating
Under dash fuse panel layout and slot function identification
Remove the lower driver-side cover to access the interior panel and read slot numbers from left to right. Each position is clearly indexed, allowing direct comparison with the printed chart on the cover.
Focus on low-amperage positions in the first row, which usually include 7.5A and 10A ratings for dashboard lighting, turn signals, and control modules. These circuits are often the first to check when small electrical features stop working.
Mid-range slots handle systems with higher demand such as audio units, accessory sockets, and windshield wipers. These positions typically use 15A ratings and are grouped together for easier identification.
Higher-load circuits like power windows and door locks are placed in separate positions with 20A ratings. If multiple door-related functions fail at once, inspect these slots before checking wiring or switches.
Use a puller tool to remove each component and inspect the internal strip. A broken or darkened bridge indicates failure, while an intact strip suggests the issue lies elsewhere in the circuit.
Always match the amperage exactly when installing a replacement, and return each component to its original position to prevent incorrect circuit routing and possible electrical damage.