Hardwiring the BlackVue Elite 9-2CH into a 2025 Mercedes-Benz GLC 350e PHEV

When it comes to dash cam installations, our customers often ask us: “Can I install a dash cam into my electric or plug-in hybrid vehicle?” and “If I hardwire it, which battery does it use?” The short answer is yes, and it uses the 12V battery, not the main EV or hybrid battery. However, because EVs and PHEVs often have much smaller 12V batteries than most regular vehicles, such as gas vehicles, diesels, or self-charging hybrids, we usually recommend a battery pack to any customer who plans on utilizing parking mode to ensure they get adequate parking mode recording time and 12V battery protection.

While we have featured a dash cam installation in a PHEV here before, in a 2023 Toyota RAV4 Prime, the owner went with our usual recommendation as it was the best option at the time. However, things have changed. Today, all three of our main brands—BlackVue, Thinkware, and VIOFO—now offer a more energy-efficient parking mode with all of their latest models. While Thinkware pioneered this with the U1000 all the way back in 2019, BlackVue’s new Elite series introduces their take, which is simply called Power Saving Parking Mode.

While Power Saving Parking Mode disables motion detection and thus lacks buffered recording, its main benefit is that it draws less than 1 mA on standby, regardless of the model, making the BlackVue Elite series the most energy-efficient dash cams to date. That’s precisely why the owner of this GLC PHEV went with the Elite 9, as it allows them to forgo the battery pack without any major drawbacks. However, just because they don’t have buffered parking mode doesn’t mean they’ll miss all the action, as they’ll wake up and start recording within 2 seconds of the impact being detected in Power Saving Parking Mode.

The first step, as with any other installation, is to pick where you want to mount your front camera. As the owner of this GLC wanted it hidden from their view while driving, the best spot to mount the front dash cam was on the passenger side, about halfway up the sensor housing. This allows the rearview mirror to fully obscure the front camera from the driver’s point of view, while also helping it remain discreet to onlookers from the outside.

Since the Elite 9 dash cam is screenless, we recommend powering the camera temporarily with the included USB-C power cable and cigarette lighter adapter (if needed) and then pairing it with your phone. Through the BlackVue app, you can live-view the camera to find the ideal mounting position and viewing angle.

Once you have chosen the location, mount the front camera onto the windshield using the provided adhesive mount. Just make sure you press the adhesive onto the windshield for at least 30 seconds to ensure a strong bond.

Now that your front camera is mounted, let’s get it wired! For the Mercedes GLC 350e, the fuse box is located in the rear cargo area, behind an access panel on the passenger side; a very common location for Mercedes models and other German vehicles. This fuse box gets its power from the 12V battery, not the hybrid battery.

Starting from the front camera, we routed the included hardwiring cable across from the passenger side of the windshield, through the headliner, to the A-pillar. Here, we removed the side panel on the dashboard, which allowed us to loosen the trim piece along the A-pillar to route the cable behind the side curtain airbag. At this point, we also connected the rear camera’s high-speed coaxial cable to the front camera, since we ended up routing them together to the rear of the vehicle.

European cars like this Mercedes have really tight and rigid interior trim, so this could be one of the toughest challenges when wiring. But with the right tools (and patience), we’re sure you can do it, and BlackVue’s thin cabling is quite helpful for this. Just be careful not to damage any of the wires or components while loosening or removing the trim pieces.

Routing the cables was relatively straightforward, as we followed our usual process of loosening the door seals and trim pieces along the B, C, and D-pillars to tuck them away behind the side curtain airbags. However, once we reached the D-pillar, we had to split the cables back up, as the hardwiring cable would be going down the D-pillar and behind the side trim into the fuse box, while the coaxial cable would go up into the liftgate.