Do I need a hardwire kit for parking mode?

Yes. Parking mode records when the engine is off, so the dash cam needs a constant power supply from the fuse box. A hardwire kit (typically £10 to £30) connects the dash cam to an always-on fuse and includes a voltage cut-off relay to protect the car battery.

Is it safe to hardwire a dash cam yourself?

Yes, if you are comfortable working with 12V car electrics. The fuse box connection uses low-current circuits and the hardwire kit includes its own inline fuse. If you are unsure, a professional installation typically costs £40 to £80 at Halfords or an independent fitter.

Which fuse should I use to hardwire a dash cam?

Use the accessory (ACC) fuse for ignition-switched power, which cuts off when the engine stops. For parking mode you also need to tap the permanent live fuse. Identify each fuse using your car handbook or a circuit tester. Always use the add-a-fuse adapter included in the hardwire kit rather than splicing existing wires.

How to Hardwire a Dash Cam UK — Step-by-Step Guide 2025

Hardwiring your dash cam removes the trailing cable from the 12V socket and unlocks parking mode — the feature that keeps recording even when the engine is off. This guide covers everything you need for a clean, professional-looking permanent install.

What Is a Hardwire Kit?

A hardwire kit connects your dash cam directly to the car’s fuse box rather than the cigarette lighter socket. Most kits include:

A fuse tap (add-a-fuse adapter) for the ignition-switched (ACC) circuit and the permanent live (BATT) circuit
A ground wire with ring terminal
An inline voltage cut-off relay to protect the battery during parking mode
Mini, standard or micro ATM fuse connectors (check which type your car uses)

Popular UK-available kits from Nextbase and Viofo are typically priced £10–£30 on Amazon.

What You Need

Hardwire kit compatible with your dash cam model
Circuit tester or multimeter
Panel removal tools (plastic trim pry tools)
Flathead and Phillips screwdrivers
Cable clips or adhesive cable management strips
Your car’s fuse box diagram (in the owner’s manual or on the fuse box cover)

Step-by-Step: How to Hardwire a Dash Cam

Step 1 — Mount the dash cam and plan the cable route

Install the dash cam at the windscreen before connecting the power cable. Plan the cable route down the A-pillar, along the headliner and to the fuse box before you start tucking wires. This avoids having to re-route later.

Step 2 — Locate the fuse box

Most UK cars have a fuse box under the dashboard on the driver’s side, often behind a removable panel. Some cars have an additional fuse box in the engine bay. Use your owner’s manual or the diagram on the fuse box lid to identify:

ACC fuse — ignition-switched. Powers off when the engine stops. Use this for basic (no parking mode) installs.
Permanent live fuse — always on. Required for parking mode alongside the ACC connection.
Ground point — a bare metal bolt near the fuse box for the earth connection.

Step 3 — Test the fuses

Use a circuit tester to confirm which fuses are ACC and which are permanent live. Switch the ignition on and off while probing to observe the behaviour. Never guess — connecting to the wrong circuit can cause electrical issues.

Step 4 — Connect the add-a-fuse adapters

Slide the hardwire kit’s fuse tap into the correct fuse slot. The tap holds the original fuse as well as its own inline fuse for the dash cam circuit. Use the amperage specified in the hardwire kit instructions — typically 5A for the dash cam and 7.5A or 10A for the original fuse.

Step 5 — Connect the ground wire

Locate a bare metal bolt near the fuse box. Remove the nut, slide the ring terminal of the ground wire over the bolt and retighten firmly. Do not attach the ground to a painted surface — bare metal contact is essential for a reliable earth.

Step 6 — Route and secure the cable

Run the cable from the fuse box along the existing wiring loom, up to the A-pillar and along the headliner to the dash cam. Use cable clips or plastic ties every 20–30 cm. Ensure the cable does not cross the steering column, pedals or any airbag cover.

Step 7 — Set the voltage cut-off

If your hardwire kit includes a voltage cut-off relay, mount it under the dashboard and set the minimum threshold. A setting of 11.6V–12.0V is typical for most UK car batteries — the relay cuts power to the dash cam before the battery drops too low to start the engine.

Step 8 — Test and refit the trim

With everything connected, start the engine and confirm the dash cam powers on. Then switch off the ignition and verify the dash cam enters parking mode and continues recording. Once confirmed, refit all trim panels and secure any loose cable runs.

How Parking Mode Works

In parking mode the dash cam draws minimal current. Recording is triggered by:

Motion detection — movement near the car activates a recording clip
Impact detection — a vibration or G-sensor event triggers recording

Most Nextbase and Viofo dash cams store parking footage separately from journey clips. Parking recordings are typically 30–60 seconds and are overwritten oldest-first once the SD card is full.

Recommended Hardwire Kits

For Nextbase dash cams, use the official Nextbase Hardwire Kit available on Amazon UK. It includes the correct connector for your model and a pre-configured voltage cut-off relay suited to UK 12V systems.

For Viofo dash cams, the Viofo HK3 hardwire kit is the recommended option. It supports both ACC and constant battery connections and works with all current Viofo models including the A229 Plus and A139 Pro.

Professional Hardwire Installation

If you prefer not to work in the fuse box, a professional hardwire installation typically costs:

Halfords: £49.99 for a front-only install
Independent fitter: £40–£80 depending on location and complexity

For a front-and-rear system with hardwiring, budget £75–£120 at most fitters. Find one at dash cam fitting near me.