The main battery fuse is typically located in the engine bay near the positive battery terminal, either inside the main fuse box or as a separate fusible link. Exact placement varies by make and model.
Where to look for the main battery fuse
The following spots cover the most common configurations found in modern vehicles. Use these as a starting point when searching for the main feed protection.
- Engine bay power distribution center (PDC) near the battery or firewall, often labeled MAIN, B+, or similar.
- A standalone fusible link directly attached to the positive battery terminal, sometimes with a red insulation cover.
- A dedicated battery junction box (BJB) located near the battery, under the hood, containing a large main fuse.
- Rear or trunk fuse blocks in some models, particularly certain European or all-wheel-drive vehicles, or cars with an auxiliary under-hood fuse block feeding high-current circuits.
If you still can't locate the main fuse, consult the owner's manual or a service manual for your exact make and model, as designs vary widely and some models place the main fuse in less obvious places.
How to identify the correct fuse or fusible link
Before you inspect fuses, verify that you're looking at the main power path from the battery. The following steps help confirm the correct component and avoid accidental damage.
- Check the vehicle's owner’s manual or service manual for the fuse box diagram and the designation for the MAIN or B+ fuse.
- Inspect the positive battery terminal area for a large inline fusible link or a heavy-duty fuse holder connected to the main power lead.
- Look inside the under-hood fuse/relay box for a large fuse labeled MAIN, B+, or a similar designation; note the amperage rating.
- If present, inspect a battery junction box (BJB) near the battery for a large fuse protecting the main feed to the vehicle’s electrical system.
- If you replace the fuse, ensure you use the exact amperage rating specified by the manufacturer and install any protective cover or seal.
Keep in mind that some modern vehicles use fusible links rather than traditional fuses, which may look like short lengths of colored wire with insulating coating rather than a conventional fuse; these must be replaced with a matching fusible link of the same rating.
Notes by vehicle type
Modern vehicles with integrated engine bay fuse blocks
In many contemporary cars, the main battery feed is routed through a centralized engine bay fuse block called the power distribution center. The main fuse or fusible link may be inside this block or as a pull-out cartridge near the battery. Always refer to the diagram on the lid or in the manual.
Vehicles with separate battery junction boxes or trunk blocks
Some models relocate the main feed to a battery junction box under the hood or in the trunk or behind a kick panel; in hybrids and electric vehicles, the main DC link or contactors may perform the role of the 'main fuse'—consult the service manual for the exact layout.
Summary
Locating the main battery fuse depends on the vehicle. The most common places are the engine bay power distribution center and a standalone fusible link near the positive terminal, but designs vary widely. Always start with the owner’s manual or service manual, use proper safety procedures when inspecting or replacing fuses, and consider professional help if you are unsure.
How much is it to replace a main fuse?
Cost of blown fuse replacement
To have blown fuses replaced, you'll usually pay a basic $100–200 service fee plus $15 per replacement fuse. This is only necessary in older homes equipped with fuse boxes instead of circuit breaker panels.
How to tell if the main battery fuse is blown?
Light. Place the clamp on ground. And then we're going to test it on the positive. If we have a complete circuit here the test light should light up right here in the handle.
Where is the main fuse for the battery?
And it says battery and it says 70 amps. So I'm going to look underneath that little sign for that fuse. Lots of interesting stuff here in your fuse box under the hood.
How to reset main fuse?
STEP 1: – What if the switch keeps on tripping?
- Switch off the Main Switch. This may be labelled “Main Switch” or just be the biggest (and probably red) switch on or next to the fuse board.
- Slowly count to 10.
- Now switch the tripped switch to “On”
- Now switch the Main Switch back “on”