Which Fuse Should You Tap for a Dash Cam?
A hardwire install needs two fuse slots. One that stays live with the ignition off, and one that only goes live when you turn the key. Tap a non-critical circuit for each, never a safety system, and fit the low-rated fuse your kit supplies on the camera branch.
This guide shows how to find the right two slots in an Australian fusebox. It also covers which circuits are safe to use, and the fuse rating question that trips up almost everyone.
The two feeds, in plain English
Your camera needs to know two things: that it has power, and whether the car is running. Two separate fuse slots tell it.
The constant feed stays live when the car is off. It is sometimes labelled B+ or BATT. This is the wire that keeps a parked camera watching.
The switched feed only carries power when the ignition is on. It is usually labelled ACC or ACCESSORY. The camera watches this wire to decide whether to record normally or switch to parking mode.
If you only want driving footage and no parking mode, you need the switched feed alone. Most people fitting a hardwire kit want both.
How to find them with a circuit tester
Start with the fuse map in your owner's manual. It names what each slot controls, which saves testing every one of them.
Then test, in this order:
- Take the key out. Clip your tester's earth lead to a bare metal bolt.
- Probe the metal test points on top of each candidate fuse. A slot that reads live with the key out is a constant feed.
- Turn the ignition on. Probe again. A slot that was dead a moment ago and reads live now is a switched feed.
- Turn the ignition off and confirm that slot goes dead again. A slot that stays live is not switched, whatever the label says.
That last step is the one people skip. Labels in a fusebox describe what the circuit powers, not when it is energised, and the two do not always match on newer cars.
Which circuits are safe to tap
The rule is simple. Tap something whose failure would annoy you, never something whose failure would make the car unsafe.
| Reasonable to consider | Do not tap |
|---|---|
| Radio or audio system | Airbags and SRS |
| 12V accessory socket | ABS and stability control |
| Interior or dome lights | Engine management and ECU |
| Central locking | Headlights and indicators |
| Powered seats or mirrors | Fuel pump and ignition |
| Spare slot, if the map confirms it is genuinely spare | Anything you cannot identify |
The right column is not a style preference. An add-a-circuit tap is reliable. But any new branch is a new thing that can fail, and a fault on an airbag or braking circuit is not one you want to meet in traffic.
Pro Tip: photograph the fusebox before you touch anything, with every fuse in place. If something behaves oddly a month later, that photo tells you exactly what was where.
Is a 20 amp fuse OK for a dash cam?
No, and the reason is where most of the confusion in this topic lives.
Search for the right rating and you will find two answers that look contradictory. Some hardwiring guides say pick a fuse slot rated between 10A and 30A. Forum threads say use a 2A to 5A fuse. Both are correct, because they describe two different fuses.
An add-a-circuit tap holds two fuses. One is the factory fuse for the circuit you tapped, and it keeps the rating it already had, which might well be 10A or 20A. The other is the new fuse protecting your camera branch, and that one should be small.
A fuse protects the cable behind it. The thin cable running up to your camera is not rated for 20 amps, so a 20A fuse would let far more through than that cable can carry before it blew. That is the failure you are trying to design out.
Use the rating your kit's manual specifies. The taps in our own install kit ship with 3A fuses for each blade size, which suits the current a dash cam actually draws.
Match the fuse tap to the shape in your car
Fuse taps are shaped to fit one type of slot. Buy the wrong shape and it will not seat, and a tap that does not seat properly is a connection that fails later.
| Fuse type | Where you tend to find it |
|---|---|
| Standard blade (ATO) | Older Australian and Japanese cars, and larger vehicles |
| Mini | Very common across cars sold here over the last two decades |
| Low-Profile Mini | Common in newer interior fuseboxes where space is tight |
| Micro2 | Widely used in recent models |
| Micro3 | Some late-model cars. Needs its own adapter and is the one most kits leave out |
Pull one fuse and compare it before you order. Our installation tools cover the four common shapes, and Micro3 is the exception worth checking for specifically.
What if your car has no switched fuse?
This is increasingly common. Many recent models, including plenty of EVs and hybrids sold in Australia, have no fuse slot that behaves like a traditional ACC feed. Every slot is either always live or controlled by a module rather than the ignition.
Your camera then cannot tell driving from parked, and parking mode either never starts or never stops. There are several ways around it, and we work through them in no ACC fuse and why dash cam parking mode fails in newer cars.
Frequently asked questions
Which fuse should I use for dash cam parking mode?
Parking mode needs the constant feed, the slot that stays live with the ignition off. Central locking, interior lights and powered seats are common choices because losing them briefly is harmless. You still need a switched feed as well, so the camera knows when to change modes.
Can I use a 10A fuse in a 5A plug?
You can physically fit it, and you should not. The fuse rating is chosen to protect the cable behind it, so fitting a higher rating means the cable is no longer properly protected. If a 5A fuse keeps blowing, something is wrong with the install rather than the fuse.
Do I need to remove the original fuse?
You remove it from the fusebox, then put that same fuse into the add-a-circuit tap. It keeps doing its original job from inside the tap. If you leave it out, the circuit it protected is now unprotected, or not powered at all.
Does it matter which way round the fuse tap goes?
Yes. An add-a-circuit tap only feeds your new branch correctly one way around. The wrong way round can leave the factory circuit running through your small camera fuse. Test with a circuit tester after fitting, before you put any trim back.
Can I tap two circuits from one fuse slot?
No. The constant feed and the switched feed have to come from two different slots. The whole point is that one is live when the other is not. You need two taps.
Not sure what your fusebox is telling you? Send Michael or Harrison your make, model and year, along with a photo of the fusebox, and we will help you read it. Talk to the Guys.
For the rest of the job, from mounting through to the cable run, see how to hardwire a dash cam in Australia.
Last reviewed: 14 September 2026. We do not install cameras ourselves; the wiring and fuse selection notes here are guidance for whoever does the work, and fusebox layouts differ between models and model years. If a specification, a feature or a claim on this page is wrong or has gone out of date, tell us and we will correct it.
Commercial disclosure: The Dash Cam Guys sells the fuse taps, install kits and hardwire kits referred to on this page, so read this as a retailer's guide to its own range rather than an independent survey of the market. No brand paid for, sponsored or supplied anything for this guide. We buy the kits we test out of our own stock, the same stock we sell. Fuse ratings and tap compatibility are the manufacturers' own published specifications, and the fuse type notes describe what is commonly fitted rather than a verified list for any specific vehicle. We do not install cameras ourselves, so the steps here are general guidance rather than a record of work we have done. If a specification, a feature or a claim on this page is wrong or has gone out of date, tell us and we will correct it.