Check the under-hood power distribution center first by releasing the side clips and lifting the cover to view labeled slots; match each amperage rating exactly before replacing any blown link to prevent damage to control modules.
The cabin electrical panel is positioned on the driver side near the lower dashboard area; remove the trim cover carefully and use the printed layout on the inside panel to identify circuits for lighting, infotainment, and accessory systems.
Use a test light or multimeter to confirm power at both terminals of each insert rather than relying on visual inspection alone, as hairline breaks are often not visible but still interrupt current flow.
High-current circuits such as cooling fans, starter relay, and trailer connections are routed through the engine compartment block, while interior components like radio, HVAC controls, and power outlets are grouped inside the cabin section for easier access.
Keep spare inserts with correct ratings such as 5A, 10A, 15A, 20A, and 30A in the glove compartment to handle roadside issues quickly, and always disconnect the negative battery terminal before working on high-load circuits.
2020 Chevy 3500 Fuse Box Diagram With Full Layout and Circuit Details
Locate the under-hood power distribution center and read the legend printed inside the cover to identify each slot; pay close attention to amperage markings such as 10A, 20A, and 40A since incorrect ratings can lead to wiring damage or module failure.
The cabin electrical block on the driver side contains circuits for radio, climate control, power windows, and accessory outlets; use a trim tool to remove the cover and cross-check slot numbers with the label before removing any component.
Each circuit is grouped by function, with high-load systems like cooling fans and trailer connections placed in the engine compartment, while low-load electronics are assigned to the interior section; this separation helps isolate faults quickly during troubleshooting.
Use a multimeter to measure continuity across each metal link rather than relying only on visual checks; a broken strip may appear intact but still fail under load, causing intermittent electrical issues.
Replace damaged elements only with identical ratings and types, keep spare inserts in the vehicle, and verify proper seating after installation to avoid loose connections that can lead to overheating or power loss.
Under Hood Fuse Box Layout With Slot Numbers and Circuit Functions
Open the engine compartment power distribution center and use the printed legend inside the cover to match slot numbers with systems; verify each position before removal to avoid disconnecting critical circuits such as ignition or control modules.
The layout is arranged by load groups, where high-current links are placed along the outer rows and smaller rated elements occupy inner sections; typical assignments include:
- Slots 1–5 for cooling fan, ABS pump, and starter relay
- Slots 6–10 for lighting circuits and horn
- Slots 11–15 for engine control unit and sensors
- Slots 16–20 for trailer wiring and auxiliary power feeds
Use a puller tool to remove each element and check continuity with a meter; always match amperage values stamped on the top and ensure the new piece fits tightly in its numbered position to prevent overheating or intermittent power loss.