Owning a Mercedes-Benz comes with many perks. As the first series-production manufacturer of modern automobiles, Mercedes has always been considered an innovator and a top producer of high-quality luxury vehicles, performance cars, off-roaders, and commercial vans. However, you may encounter a few issues and quirks when installing a dash cam. In this article, we will share our insights on common Mercedes-Benz installation issues and recommendations on installing your dash cam.
Delayed ACC fuses are ACC fuses that remain powered for approximately 15 minutes after the vehicle is turned off, and are found in many Mercedes models. Also commonly found in vehicles from BMW, Ford, and GM, they can easily be mistaken for constant fuses and distinguishing between them is challenging. Many delayed ACC fuses will get “tripped” and turn back on when basic functions of the vehicle are performed, such as opening a door or using the key fob.
To properly identify such fuses, we recommend testing them initially, then leaving the fuse box cover and closest door open for 15~ minutes and returning to them for testing, a practice we follow in all of our Mercedes installs. Any fuses that lose power during that waiting period are your delayed ACC fuses, while the ones that remain powered are your constant fuses. Testing should be done with a circuit tester or multimeter.
Some Mercedes’ fuseboxes, but not all, are located in the rear of the vehicle—usually in the trunk or under the rear seat. Even if there is a front fusebox, it is unlikely that it will have both the ACC and constant connections required for the hardwired installation. This makes powering the front dash cam unit more challenging. If this sounds like your Mercedes, you’ll need to wire from the trunk or underneath the rear seat to the front unit.
It’s important to measure the distance to ensure that your hardwiring cable is long enough to reach the front camera first. The same applies to the output cable if you’re using a battery pack. We highly recommend an extended hardwiring cable to cover the distance in most setups, though the long cabling of some brands like BlackVue can be sufficient.
In some Mercedes models, like the W204 C-Class, W164 M-Class, and X164 GL-Class, the cigarette socket ports stay on when the vehicle is off. Cigarette lighter ports that stay on when the vehicle is off are unusable for powering a battery pack or a dash cam, as there’s nothing to prevent them from fully draining your 12V vehicle battery. If this sounds like your Mercedes, we firmly do not recommend connecting a cigarette lighter adapter for either a dash cam or battery pack.
Thankfully, if this is a concern for you, it’s incredibly easy to test, as connecting any appliance to the cigarette socket and noting if it stays on when the vehicle is off will confirm if this issue is relevant to your vehicle. Some models, like the W211 E-Class, allow you to change how the 12V cigarette socket operates by repositioning its fuse—something we’ve also seen in certain Chrysler and GM vehicles. If you notice that your cigarette lighter ports are staying on with the ignition off, it’s worth checking if this is possible for your Mercedes model.
Mercedes, like other European brands, builds its vehicles with very tight-fitting interior trim, making wiring more difficult to neatly hide. This is particularly an issue with certain dash cam makes or models, like VIOFO, which have thick and somewhat rigid cables that typically cause the interior trim to bulge or otherwise not fit properly. Dash cams from brands like BlackVue, FineVu, Philips and Thinkware use thinner or more flexible cables that are much easier to run and hide behind the tight-fitting interior trim in your Mercedes.
Some Mercedes models, particularly coupes, convertibles, and sedans, have rear seatbacks that are fixed in place. While they often have limited recline adjustments, these seatbacks don’t fold down, unlike the ones you’d find in a typical coupe or sedan. If you plan on wiring into a trunk-mounted fusebox in such a Mercedes model, this may make it slightly more challenging, but it can still be done. You may be able to use a gap between the seatback and the side of the vehicle or run the cables up the C-pillar; this depends on how your model is configured. Here’s how we did it in a 2018 E450 Coupe and 2019 S63 AMG Sedan.
While installing a dash cam in your Mercedes-Benz vehicle can be a bit challenging, there are a couple of options you can consider to make the process easier.
While wiring to a rear fusebox may be more challenging, the OBD port can still provide a properly switched power source. This method is often more convenient, eliminating the need for complex wiring, and can be accomplished relatively easily. OBD installation is an easy plug-and-play solution, which enables all the same features you get with hardwiring, including voltage monitoring.
The most limiting factor is that OBD installation is only available for certain camera brands with OBD cables, such as Thinkware and FineVu. It’s also worth noting that OBD ports cannot power battery packs due to their low output and may not be available in older or imported models. Learn more about OBD Power Installation here.
If your Mercedes has switched cigarette sockets that only operate when the vehicle is running or can be configured to operate that way, you’ll have no problem installing a battery pack like our PowerCell 8 via the cigarette lighter adapter (CLA).
Aside from being another simple plug-and-play solution for parking mode, several perks come with using battery packs. A hardwired or OBD-powered dash cam can only run in parking mode between 6-8 hours, depending on the vehicle model, before shutting off. A battery pack eliminates this issue by providing your dash cam with a dedicated power source for parking mode, while providing significantly more runtime and removing all wear and tear on your vehicle battery.
Battery packs are especially beneficial if your Mercedes is an EV or hybrid. We’ll talk more about EVs here later, but most EVs and hybrids have much smaller 12V accessory batteries than conventional gas and diesel vehicles, meaning hardwired or OBD installations suffer from significantly shorter runtimes (usually halved). The additional runtime a battery pack provides not only eliminates this issue, but provides the same benefits or enhanced runtime and battery protection as well. Learn more about battery packs & EVs here.
As a longstanding innovator in the automotive industry, it’s no surprise that Mercedes has been a key player in the electrification of the automobile. They began with their first hybrid vehicle in 1906, nearly 120 years ago, and followed up with their first pure electric car in May 1990.
These early attempts were quite rudimentary, but the same no longer holds true for their latest electric vehicles. Instead, they’re highly sophisticated and technologically advanced, thus presenting their own unique challenges when it comes to dash cam installations.
Applicable vehicle models include but are not limited to:
The fundamental issue is the lack of easily accessible interior ACC (Accessory) fuses in Mercedes EVs. This is a problem as dash cams require both a constant power connection and an accessory connection when hardwiring, while battery packs must only be hardwired to accessory power.
This accessory connection indicates to most cameras when to go into parking mode, a low-power state that draws power from the vehicle’s battery, monitoring the voltage so it doesn’t draw too much. If parking mode is not engaged, most cameras will not monitor the voltage and will draw significantly more power, potentially resulting in a dead car battery. For Battery Packs, the accessory connection instead is the only fuse it is wired to, and is used to communicate to the camera when to go into parking mode.
While these vehicle models typically have several interior fuse boxes that are relatively easy to access, we’ve found that they are often fully constantly powered. Still, it’s always worth checking the fuse boxes, using a circuit tester or multimeter to verify the nature of the fuses. Some models do have fuse boxes with ACC connections but these are typically in difficult-to-access locations, so wiring to them is quite challenging.
While the following procedures can be done at home, provided you have the necessary skills, any mistakes can damage your electrical system and leave your vehicle inoperable. If you are unsure of your technical abilities, we wholeheartedly recommend speaking to a professional. Any reputable auto electrician, particularly those familiar with Mercedes vehicles or luxury EVs in general, should be able to complete the installation using these methods. Our in-house installers have completed installations into many Mercedes EVs doing so with no issues.
Even if your vehicle doesn’t have any ACC fuses, ACC power still flows through the wiring in your vehicle, which can be spliced into. Splicing into existing wiring in a vehicle typically involves carefully cutting into the insulation of a wire in the vehicle's electrical system and then connecting another wire to it. It's important to identify the correct wires and use proper techniques to ensure a secure and reliable connection without causing damage to the vehicle's electrical system. That said, it’s important to note that splicing is a destructive process which may void your vehicle’s warranty. Options like T-taps can help with the process, and make it less intrusive.
Lastly, if you plan on getting a battery pack hardwired, consider having it set up with a relay. If your vehicle does not have any suitable ACC fuses for a battery pack installation, a relay setup interfaces with any non-essential ACC connection to act as a switch. It allows the battery pack to draw from a suitable constant connection only when the vehicle is running, acting as a countermeasure to protect your vehicle’s battery and electrical system. Depending on your vehicle, this may either be done with or without splicing.
Also known as the G-Wagon, the Mercedes G-Class is widely considered Germany’s legendary off-roader. In production since 1979 with very few fundamental changes, the G-Class remains a popular choice for those in the market for a serious, high-performance off-roader—or those simply seeking a rock-solid, military-grade SUV. However, owing to its long production run and old-school design, it has some quirks that make rear camera installations a bit different from what you’d expect of a typical modern SUV.
Like many SUVs and off-roaders with a rear spare tire carrier, most G-Wagens have a side-hinged rear door that opens like a conventional car door. Since the G-Class has a fixed rear window, you won’t have any issues installing your rear camera directly onto the glass, running the connecting cable into the rear door through a suitable rubber grommet near the hinges. However, unlike a top-hinged hatch as found on other Mercedes SUV models, there’s an extra bit of distance you’ll need to cover when making this run. Thus, it’s important to ensure that your rear camera connecting cable is long enough to reach the rear unit by measuring the distance before installation. While most rear connecting cables we’ve worked with are long enough to make this run, you may need to purchase a longer one to cover the distance. See how we installed a 2-channel dash cam into a Mercedes G-Class here.
While most G-Wagens are traditional SUVs with fixed solid roofs, some variants like the Cabriolet and Maybach Landaulet have soft tops that retract or come off entirely. Fortunately, we’re no stranger to vehicles like this, which we’ve dubbed Off-Roadsters. While the traditional rear camera mounting location won’t work for these variants, the rear camera can still be mounted on the vehicle’s roll cage or in another suitable location. Check out our full guide on Off-Roadster dash cam installations here.
While Mercedes is best known for its luxury cars, high-performance AMG models, and G-Class off-roaders, they’re also one of the world’s leading manufacturers of commercial vans like the Metris and Sprinter. If you’ve ever taken an airport shuttle or had a package delivered by van, there’s a good chance it was a Mercedes. However, commercial vans in general do come with additional challenges for dash cam installations, and Mercedes vans are no different.
Mercedes vans come in all shapes and sizes, from Metris minivans that fit nicely into a typical household garage, to extended-length, high-roof Sprinters as long and tall as a small bus. Because of this, you’ll often find that the standard-length rear camera connecting cables are not long enough for these vans. Fortunately, many dash cam brands like BlackVue and Thinkware offer extended rear connecting cables to make installations possible in these longer vehicles.
Much like the G-Class, many Mercedes vans have rear barn doors that are hinged on the side. This applies mainly to the Sprinter, which all come with barn doors, but can also be found on some examples of their smaller vans like the Metris. Fortunately, if your Mercedes van’s barn doors have windows, the advice for the G-Class above will also apply here. The key is to measure the distance to ensure the rear connecting cable is long enough and use a longer cable if needed.
While some Mercedes vans—particularly passenger models—have windows on their rear doors, many cargo and utility models do not. This is an issue if you want to install a rear camera on one of these vans since the only suitable location is the van’s exterior, but most typical rear cameras aren’t weatherproof. Thus, you’ll be limited to models that include or support external rear cameras like the BlackVue DR770X-2CH Truck or the Thinkware Q200 with Exterior Infrared Camera.
As you’ll be wiring from the van’s interior to the exterior mounting location, there may not be a suitable entry point or rubber grommet to wire through, meaning you will have to drill through the van body to get the cable outside. Some external rear cameras like BlackVue’s will also have to be bolted into the van body, a permanent installation. Any mistakes could lead to rust, water leaks, or compromised structural integrity, so these installations should only be attempted by experienced individuals or done professionally.
And that’s how you can work around the common dash cam installation issues with Mercedes-Benz vehicles! For more general advice on installations, check out our dash cam installation hub here. If you’re in or near the Vancouver, BC area, you can book an appointment with our professional installers here.
For more questions or installer recommendations local to your area, please reach out to our support team here.
