Hardwiring a Dash Cam for BMW & Audi Vehicles

Most BMW fuseboxes, while not all, are not as easily accessible as your average vehicle. Instead of being up at the front of the vehicle, they are located in the rear of the trunk. Even if there is a fusebox in the front of the vehicle, it is unlikely that it will have both the constant, and ACC(Ignition-based) connection required for the hardwire installation.

To properly hardwire the camera, you’ll need to run the cable all the way from that rear fusebox in the trunk to the camera on the front windshield. While some dash cams are mounted in a way that allows professional installers to accomplish this with the stock hardwiring kit, many vehicles or camera models will need an extended wire to cover the distance.

BMWs, like other European car models, have very thin panelling, making wiring more difficult, especially when combined with how far the cable must be run from the trunk. Camera models with thick cabling, such as VIOFO, are not ideal for wiring into BMWs. Brands like BlackVue and Thinkware are ideal for wiring into a European vehicle like this, offering an easier and cleaner installation.

BMWs fuseboxes themselves also have plenty of traps that are not ideal to wire to such as Delayed ACC fuses. Delayed ACC fuses are fuses that are not proper constant power connections - they continue to operate for approximately 15 mins after the car’s turned off. Determining which of the fuses are delayed ACC and which are standard is challenging. Many delayed ACC fuses will get “tripped” turning back on when basic functions of the vehicle are performed, such as opening the car door, or unlocking it with your keys.

To avoid such issues, we recommend leaving the door that accesses the fusebox ajar for 15~ minutes, and returning to the fusebox at that time for testing, a practice we follow in all of our BMW installs. Any fuses you are wiring to, that previously indicated power once the vehicle has been turned off, should be tested using a circuit tester or Voltmeter.

Looking to learn the basics of Add-A-Fuses? Check out our Add-A-Fuse Guide here.

While hardwiring is recommended, issues can still be experienced due to BMW batteries. BMWs do not like any kind of excess power drain on the vehicle’s battery once the vehicle is turned off. Generally, their electronic systems remain over-sensitive and can display error codes on the dashboard, indicating battery discharge while the car was parked.

We have observed that in newer, 2021+ BMW models, this can even disable all electronics and vehicle functions soon after the car is off, including key signals, overhead lights, and the dash cam itself. These functions will be restored once the vehicle is turned back on manually.

In any case, returning to the vehicle and seeing a warning sign never feels great. You are able to avoid this by setting a very high voltage cut-off on your dash cam, but that frequently feels counterintuitive, since it limits the duration of parking mode that you’re wired to the fusebox for. With a high voltage cut-off, parking mode will likely only last for a couple hours at most.