How to Hardwire a Dash Cam: Fuse Box, Cable Route and Parking Mode
Hardwiring a dash cam means powering it from the fuse box instead of the 12V socket. A hardwire kit converts the car's 12 volts to what the camera needs, the cable is hidden along the headlining and pillar, and the camera turns on with the car. With a constant power lead and a low-voltage cut-off, it can also record in parking mode without flattening the battery.
What you need
- A hardwire kit made for your camera: it has the right plug and usually a low-voltage cut-off.
- Fuse taps: add-a-fuse holders that let you draw power from a fuse slot without cutting wires. They must match your car's fuse type.
- A trim tool: to tuck the cable under the headlining and pillar trim without damage.
- A test light or multimeter: to find which fuses are switched and which are constant.
How it is done
- Mount the camera: behind the rear-view mirror, out of your line of sight.
- Route the cable: along the top of the windscreen under the headlining, down the pillar beside the door seal, and under the dash to the fuse box.
- Keep clear of the airbag: many pillars hide a curtain airbag. Run the cable behind it, never across the front where it could block the airbag.
- Find a switched fuse: one that is only live with the ignition on, for normal recording.
- Find a constant fuse: one that is always live, if you want parking mode.
- Fit the fuse taps: facing the right way, with the correct fuse rating.
- Earth the kit: to a bare metal bolt on the body, not a painted or plastic part.
- Set the cut-off and test: choose the cut-off voltage, then check the camera starts with the car and switches to parking mode when you turn it off.
Mistakes to avoid
- Using a fuse for a safety system, such as airbags or ABS.
- Running the cable across the airbag or where it can be pinched by trim.
- A poor earth, which causes the camera to reboot or record nothing.
- Setting the cut-off too low, so a weak or small battery cannot start the car. Hybrids such as the Aqua and Prius have a small 12V battery, so set it conservatively.
When you do not need to hardwire
If you do not want parking mode and do not mind the cable, the 12V socket plug works fine. Hardwiring is worth it for a tidy finish and parking mode. Read whether parking mode drains the battery before you decide.
Have it fitted
If you would rather not work near airbags and the fuse box, we hardwire dash cams at your home or work. See dash cam installation, and our dash cam buying guide for NZ if you are still choosing a camera.
Frequently asked questions
Which fuse should I use for a dash cam?
A switched fuse that is only live with the ignition, such as an accessory or socket fuse, for normal recording. Add a constant fuse only for parking mode. Avoid fuses for safety systems.
Can I hardwire a dash cam myself?
Yes, if you are comfortable with trim, fuse taps and a test light. The main risks are the airbag in the pillar and choosing the wrong fuse.
Will a hardwired dash cam drain my battery?
Not with a switched fuse only. With parking mode on a constant fuse, it draws power while parked, so the low-voltage cut-off must be set to protect the battery.
Do I need a hardwire kit for parking mode?
Usually yes, or a dedicated dash cam battery pack. Parking mode needs power when the car is off, which the 12V socket in most cars does not give.