VIOFO HK3-C Hardwire Kit User Manual & Setup Guide
VIOFO HK3-C Hardwire Kit acting up? Lost the booklet? No stress.
You've got the VIOFO HK3-C Hardwire Kit to run your VIOFO in parking mode, but the instructions went out with the box. No dramas. Below you'll find the specs, the wiring, the cut-off voltage options and fixes for the most common issues.
💡 Pro Tip: Don't Forget the Fuse Taps!
Fuse taps aren't included with the HK3-C, and jamming bare wires into a fuse box is asking for trouble. For a clean, safe install, use the correct Add-A-Circuit Fuse Taps for your vehicle.
Quick Specs
- Output connector: USB Type-C plug, DC 5V 2A
- Input voltage: 12–24V
- Total cable length: 4 m
- Wires: Red (Battery), Yellow (ACC), Black (Ground)
- Battery protection options: 11.8V / 12V / 12.2V / 12.4V (24V systems: 23.6V / 24V / 24.4V / 24.8V)
- Working temperature: -30°C to 60°C
- Protection: Low voltage, over current/surge and reverse polarity protection
- Fuse taps: Not included
Compatible cameras: VIOFO lists the A139 and A139 Pro (1, 2 and 3-channel). It's USB-C only, so the older Mini-USB A119 V3 and A129 cameras need the Mini HK3, and a VS1 takes the HK5.
Installation Steps
Before you start, set up your parking mode options in the camera (VIOFO app or camera menu), and make sure the engine and accessory power are off.
- Locate your fuse box. Fuse boxes and fuse types vary by model, year and variant, so check your car's manual for the location and fuse type.
- Find a constant (Battery) fuse. With the ignition locked, use a test light on the fuse's exposed metal contacts. You want one that's live even when the car is off.
- Find a switched (ACC) fuse. Turn the ignition to ACC and look for a fuse that's live in ACC but dead when the ignition is off.
- Find a ground point. Pick a screw or bolt connected directly to the vehicle body. On a multimeter's continuity mode it should read under 0.1 ohm to the body.
- Crimp on your fuse taps. Crimp an Add-A-Fuse tap onto the Red and Yellow wires with a crimp tool or needle-nose pliers.
- Connect it up. Yellow (ACC) into the switched fuse slot, Red (Battery) into the constant fuse slot (the connection must be made after passing through the fuse), and the Black ground spade under your ground screw, tightened down.
- Test before tidying. Plug the USB-C into the camera, start the car and check it powers up, then turn it off and check it goes into parking mode. Only then tuck the cables behind the trim.
Voltage Cut-Off Settings (The Important Bit)
The HK3-C powers your camera in parking mode until the car battery drops to the level you've chosen, or until the camera's parking timer runs out (set the timer in the VIOFO app).
Note: We generally recommend 12.2V or 12.4V for most Aussie daily drivers to keep your battery healthy.
| Option | 12V Batteries (Cars/Utes) | 24V Batteries (Trucks) |
|---|---|---|
| 1 | 11.8V | 23.6V |
| 2 | 12.0V | 24.0V |
| 3 | 12.2V | 24.4V |
| 4 | 12.4V | 24.8V |
Common Questions & Troubleshooting
Which wire goes where?
Red goes to a fuse with power all the time (Battery). Yellow goes to a fuse that's only live with the ignition on (ACC). Black goes to a bare metal bolt or screw on the body (Ground). If Red and Yellow are swapped, parking mode won't work properly, so just swap 'em over.
The camera isn't going into parking mode.
Usually the Yellow (ACC) wire is on a fuse that stays live after the car is switched off, so the camera thinks you're still driving. Re-test with the key out and pick a fuse that drops out straight away. Also check parking mode is actually turned on in the VIOFO app.
The camera turns off when I turn the car off.
The Red wire isn't getting constant power. Check it's in a fuse slot that stays live with the ignition off, and that the fuse tap crimp is tight.
My car battery went flat even with the kit installed.
Check your cut-off setting. 11.8V can be too low for an older battery on a cold morning. Bump it up to 12.2V or 12.4V, or set a shorter parking timer in the app.
Nothing powers up at all.
Check the ground. The Black wire must be firmly on a bolt with direct contact to the vehicle body, not painted trim or plastic. Then check the fuse taps are seated properly and the fuses in them are intact.
Should I DIY this?
VIOFO recommends the kit is installed by a professional. If you're not confident testing fuses, get an auto electrician or installer to do it for peace of mind.
Official User Manual
Here is the full diagram and instruction sheet straight from VIOFO.
Last reviewed: 17 September 2026. We do not install cameras ourselves; the wiring notes here are guidance for whoever does the work. The specifications, cut-off voltages and installation steps follow VIOFO's own manual for this kit, and revisions can change them, so check the current manual if something does not match. If a specification, a feature or a price on this page is wrong or has gone out of date, tell us and we will correct it.