Check the interior and engine compartment power panels first when electrical components stop working. Use the cover legend and amperage ratings to match each slot with its circuit before removing any part. This reduces the risk of damaging sensitive systems such as lighting, infotainment, or safety modules.
The cabin panel is typically located under the dashboard on the driver side, while the engine bay unit sits near the battery. Each slot is assigned to a specific circuit, including headlights, wipers, climate control, and charging ports. A clear layout helps trace faults quickly without disassembling unrelated parts.
When inspecting a blown link, look for a broken metal strip inside the casing. Replace it with the same amperage rating only. Using a higher rating can lead to wiring damage or component failure. Keep a small puller tool in the vehicle to remove parts safely without bending contacts.
Accurate slot mapping also supports troubleshooting intermittent issues, such as power loss to accessories or warning lights on the dashboard. Cross-check the layout with the vehicle manual to confirm assignments before testing relays or connectors.
2019 Mazda 3 Fuse Box Diagram Locations and Fuse Assignment Guide
Locate the cabin electrical panel under the left side of the dashboard and the engine compartment unit near the battery, then match each slot using the cover legend before removing any component.
The interior panel handles low-current systems. Typical slot assignments include:
- Multimedia system and display module
- Power windows and mirror controls
- Interior lighting circuits
- Accessory outlets and USB charging ports
The engine bay distribution unit supports higher loads and critical systems. Check labeled positions for:
- Cooling fan and radiator control
- Headlights and daytime running lamps
- ABS and stability control module
- Engine management and ignition circuits
Each slot uses a color-coded amperage rating, such as 10A for small electronics and 30A or higher for motors. Always replace with identical rating to avoid overheating or wiring damage. Use the plastic puller stored in the panel cover to remove components without bending terminals.
For quick identification, follow this sequence:
- Find the correct panel location
- Read the legend printed inside the cover
- Match the circuit name with the slot number
- Inspect the metal strip inside the component
- Install a new unit with the same rating if damaged
Where to find fuse boxes in 2019 Mazda 3 and how to access them
Open the driver-side lower dash panel and check behind the small plastic cover near the steering column to reach the interior power distribution unit.
This cabin panel is secured with clips. Pull the cover gently from the edge; no tools are required. Inside, you will see rows of small blade-type links arranged in a grid, with a legend printed on the back of the cover indicating circuit names and slot numbers.
Engine compartment location
Release the hood and look near the battery on the left side of the engine bay. The main electrical housing is a black plastic case with a snap-on lid. Press the locking tabs and lift the cover to expose larger cartridge-style links and relays connected to high-load systems.
Access in this area requires the engine to be off and cool. Avoid touching metal contacts directly. The layout inside the lid shows circuit groupings such as cooling system, lighting, and control modules.
Access tips and precautions
Keep a plastic puller tool inside the vehicle for safe removal. Ensure the ignition is off before handling any component. Align the cover properly when closing both panels to prevent moisture or dust from entering the electrical housing.