How to read a fuse box chart (and replace a fuse safely)
A fuse box chart lists each fuse’s position (the number or label molded next to its slot), its amp rating, and the circuit it protects. Find the circuit that stopped working, note its position, and check that fuse. Replace it only with a fuse of the same amp rating.
Where are the fuse boxes?
Most vehicles have two or more: one in the engine compartment and one inside the cabin (under the dashboard, at the side of the instrument panel, or in the trunk). Your owner’s manual shows where. The Chevrolet Avalanche listing, for example, covers the engine compartment fuse block, and the Honda Fit listing includes a small box on the battery terminal.
Reading the listing
- Position: match it to the number or label on the fuse box or its cover. Ford listings number every fuse and relay, as in the Ford Flex; GM often uses short labels such as “HTD STR” (heated steering wheel).
- Amps: the rating printed on the fuse. Some GM listings give the circuit but not the amps; read the rating off the fuse itself.
- Relays are listed with the fuses but aren’t fuses: a relay is a switch, and it’s tested and replaced differently.
- A blank or “Not used” position is a spare slot.
What do the fuse colors mean?
Standard blade fuses are color-coded by rating: 5 A tan, 10 A red, 15 A blue, 20 A yellow, 25 A clear or natural, 30 A green. The number on top is what counts; check it before you install a replacement.
Replacing a fuse safely
- Turn the vehicle off first. Most fuse boxes hold a fuse puller and sometimes spare fuses.
- A blown blade fuse has a broken metal strip inside.
- Never fit a higher-rated fuse or bridge the slot: the fuse is there to protect the wiring.
- If the new fuse blows again, there’s a fault in that circuit. Have it checked.
- Large high-amp fuses in the engine compartment are often meant to be replaced by a dealer; the Honda Fit manual says so for its engine compartment fuses.
Browse every listing in Fuse box charts by vehicle.