Hardwiring a dash cam is a popular choice as many users want to keep the power cables out of sight making for a cleaner install. It will also free up a cigarette socket in your vehicle which can be left for use with a phone charger, GPS, or other automotive accessory. There are a number of different hardwire kits on the market: Some which power the dash cam only when the vehicle is running such as our mini USB hardwire kit; some power the dash cam while the vehicles is off in parking mode using the car's battery such as the Multi Safer or Thinkware hardwire kit; and some which power the camera in parking mode using its own battery such as the Cellink Battery B. While these kits differ slightly in their configuration, the installation is more or less the same and once you learn how to install one, you should be able to install the other types with no issues!
1. Locate the Fuse Box
Consult your owner's manual for the location of the fuse box, if you've misplaced the owners manual you may be able to find this information online. You may need to remove some trim or open some panels to gain access to the fuses, on some cars these will open simply by lifting a tab or pulling a panel with your fingers but other cars may require prying with our supplied trim tool. There are many different ways to access a fuse box and the owner's manual should offer some insight on how to do this.
This is a sample owners manual which shows how to access the fuse box in a Mazda 3 (left) and a Mazda CX-5 (right)
2. Locate the Fuse Chart/Diagram
Once you've found out where the fuse box is located, you should also look into the layout of the fuse box. If there are any spare or empty fuse slots in the vehicle, we will typically try to use these slots as it won't require removing any existing fuses. That being said, some vehicles just don't have empty fuse slots in their interior fuse box so you will need to power your dash cam using existing fuses. If this is the case, you should refer to the vehicle's fuse diagram to find fuses that will be safer to run an accessory off of. We recommend looking for fuses such as power outlets, accessory fuses, heated seats, fog lights, or dome lights. You should avoid using fuses for air bags, ECU, traction control, and features of that sort that would relate directly to the safety of the vehicle.
This is a sample fuse chart from the owner's manual of a Ford F-150. The fuse slots are all numbered and the chart indicates what features are associated with the fuse
The fuse chart may be in a number of different places. The most common place to find the fuse chart or fuse diagram is the owner's manual. If you've misplaced your owner's manual you may be able download a digital version on the vehicle manufacturer's website. Japanese manufacturers typically have it printed on the fuse panel cover or nearby it. German manufacturers such as BMW or Mercedes may have it printed on a folded piece of paper in the fuse compartment.
3. Find the Correct Fuse Slot for your Hardwire Kit
Check with your hardwire kit or battery pack to see if you need ignition switched power, constant power, or both. You will need a circuit tester or multimeter to test if a fuse is ignition switched or always on. If you are testing an empty fuse slot, put the tip of your tester into the slot directly, if you are testing on fuse slots that have existing fuses in them, you can test using the openings on the top of the fuse. If you need to find an ignition switched fuse, make sure to have your key in the vehicle so you can test that the fuse is off when the car is turned off but turns on and stays on as soon as your car is in a key-on position. If the fuse stays lit up even after you turn off the car, try to use a different fuse slot. If a fuse is not lit up while the car is off, do not assume that it is an ignition switched fuse, make sure to test it by turning the car on to see that it lights up.
This picture shows a circuit tester lighting up when poking into the ports on top of a fuse
If your kit requires constant power, turn off the car and remove the key to see which fuse slots remain on. With newer vehicles, BMW in particular, there may be timed fuses which are computer controlled and stay on for a set number of minutes after the car is turned off. For newer BMW's we leave the door or trunk open for 30 minutes to let the timer run out. Opening or closing and locking or unlocking will reset this timer but you can proceed with running the rest of your dash cam's wiring while you wait as long as you don't reset the timer accidentally.
4. Connect the Add-A-Fuse
Once you've determined which fuse slots you need to use for your hardwiring kit you can crimp your hardwire kit onto the Add-A-Fuse. You should be able to crimp the fuse kit with a standard needle nose plier. We also recommend using electrical tape to further secure the wire. If you are using a fuse slot that has an existing fuse in it, put that fuse in the lower fuse slot of the Add-A-Fuse and plug the new setup into the fuse box in the correct orientation. For more on the Add-A-Fuse, see our Add-A-Fuse guide here.
5. Ground the Hardwire Kit
Once you've connected the power of your hardwire kit, you can connect the ground which is usually in the shape of a ring or a C to slip under a metal bolt or screw in your vehicle. You will typically need a socket wrench set to loosen the nut or bolt that you choose to ground with. The most common sizes in our experience are 10mm and 12mm although some German cars may use Torx (6-pointed star) bolts. To attach the grounding terminal, loosen the nut or bolt enough to slip it in and tighten it back up afterwards. A loose ground can result in power issues for your dash cam.
It's best to ground with a bolt on unpainted bare metal, if a bad ground is chosen it may cause restarting on the dash cam when the current is unable to flow consistently. Even if the bolt is metal, if the grounding terminal of the hardwire kit is fastened onto a plastic surface, you may come across issues. If you can find a factory ground (see picture above) this is an ideal grounding spot for your hardwire kit.
Once you've hooked up the power and ground, plug the kit into your camera and start your car to see if it works. If it works you can run and tuck all the wires in to your car, we recommend taping or zip tying the excess wires out of the way so it doesn't block any access to your fuse box. Make sure wires are not dangling where they may be kicked when you are getting in and out of the car as this can cause damage to your hardwire kit or vehicle. You shouldn't wait till after you've tucked away all your wiring to plug in and test your camera as it will typically be easier to troubleshoot when the wires are readily accessible. Once you've completed and verified all these steps, give yourself a pat on the back as you've successfully installed your hardwire kit!
Troubleshooting Your Install
Now we'll go through some of the common mistakes and troubleshooting that we go through when a hardwire kit is not working as expected
- Reversed orientation of the accessory and ignition switched wires - the dash cam will behave abnormally if the wires are switched and in some cases even result in battery drain. Please double check with your specific hardwire kit for the wire orientation and don't go off other guides
- Bad Ground - When an incorrect ground is used the camera won't get power. A loose or weak ground may result in restarting when the vehicle hits a bump.
- Add-A-Fuse incorrectly set up - If you don't put a fuse into the top fuse slot of the add-a-fuse, it will not feed power to the hardwire kit.
- Blown Fuse - If the fuse on the add-a-fuse is blown, the kit will not receive power. There might also be inline glass fuses on the cigarette cable or hardwire kit that can also be blown.
- Loose Wire in Add-A-Fuse - On some hardwire kits, the wire is much thinner than the socket on the add-a-fuse. Because of this, they may wiggle loose in the add-a-fuse leading to an inconsistent current. Make sure that the crimp is tight and the wire is held in tightly.