Garmin Constant Power Cable (OBD-II) Review: 7.6/10
A $50 cable that some owners call “set it and forget it,” while others say it “never shuts down” and “completely discharges” a brand-new battery—Garmin Constant Power Cable for Dash Cam (OBD-II) lands as a Conditional buy at 7.6/10 based on cross-platform user feedback.
Quick Verdict
For drivers who want a clean, no-fuse-box install for a Garmin dash cam, the Garmin Constant Power Cable for Dash Cam (OBD-II) is often praised as a fast “plug and play” fix. But digging deeper into user reports, a recurring pattern emerged: on certain vehicles, the timer behavior and battery draw can be unpredictable, turning “constant power” into an unwanted all-night recording session.
The strongest endorsements come from people who hate hardwiring and just want parking mode coverage with hidden wiring. A verified buyer on Amazon noted: “Super easy to install,” adding it worked smoothly with “a Honda HRV 2019.” On Best Buy, a reviewer echoed the same vibe, saying it “took me less than 15 minutes” and the wiring “looks 100% professional.”
The sharpest warnings come from owners whose cars don’t seem to cooperate with the shutoff logic. On Best Buy, user Bill said: “Works perfectly on the bronco but never shuts down on the hyundai and completely discharges it’s brand new battery.” On Reddit, a post described a similar scenario: after using the “10 minute option,” the camera “has been recording nonstop… from 9pm… all night until 8am.”
| Verdict | Evidence from users | Who it’s for |
|---|---|---|
| Conditional | Timer can behave differently by vehicle | Owners comfortable monitoring first week |
| Pro | “Super easy to install” (Amazon) | Drivers avoiding fuse-box hardwire |
| Pro | “Wire is all hidden… professional” (Best Buy) | Clean interior / stealth installs |
| Con | “Does what it’s supposed to, pricey” (Amazon) | Value-sensitive buyers may resent cost |
| Con | “Never shuts down… discharges… battery” (Best Buy) | Cars sensitive to OBD draw/timers |
| Con | “Mine functioned great… now… can’t use it” (Amazon) | Buyers expecting long-term reliability |
Claims vs Reality
One of the big marketing promises is constant power “even when the vehicle is parked and turned off.” In practice, many users love exactly that—especially those trying to keep parking recording alive without tearing into the fuse panel. A verified buyer on Amazon described it as “a very elegant solution,” emphasizing they “didn’t have to splice any wires” and liked that it “will accept two cameras at once since it has two usb ports.”
But the same “always available” power becomes the controversy when the timer doesn’t behave as expected. On Reddit, a user troubleshooting the 10-minute mode wrote that after months of normal behavior, their dash cam began “recording nonstop” overnight despite being “on the 10min setting.” That kind of report doesn’t necessarily contradict the product’s promise of constant power—but it clashes with buyers’ expectation that the timer will reliably cut power when configured.
Another official talking point is battery protection via low-voltage cutoff (often described around 12V). While the manufacturer frames this as dead-battery prevention, user experiences show mixed outcomes depending on vehicle and usage patterns. On Amazon, one reviewer said “the shut off works well to avoid draining the battery,” presenting the cable as a workaround for “modern cars” that “freak out” with hardwiring. Meanwhile, Best Buy user Isaiah still warned: “watch out for drawing off your battery if you leave this plugged in all the time.”
A final promise baked into the product concept is simplicity: plug into OBD-II and go. Many buyers confirm the install is straightforward, but some report the switch and settings can trip people up. A verified buyer on Amazon said “the setting button is hard to see and is off set,” explaining they put it “in the wrong position” and thought the battery was down—until they corrected the setting.
Cross-Platform Consensus
Universally Praised
“It literally just plugs into the port”—that’s the core reason this cable keeps getting purchased even at a premium price. Across Amazon and Best Buy, a recurring pattern emerged: users who prioritize a clean, low-effort install feel like this accessory finally makes parking mode approachable. A verified buyer on Amazon wrote: “It was so simple to use, it literally just plugs into the port,” framing it as an end-run around splicing, awkward routing, and fuse-box work.
For drivers who obsess over interior aesthetics, the “hidden wire” benefit shows up as an emotional payoff: the install looks intentional, not improvised. A verified buyer on Amazon said it “clips in low and out of sight” with “a nice, sleek looking” setup. On Best Buy, another reviewer described routing along the door molding and concluded the wire was “all hidden and looks 100% professional.” That’s not just convenience—it’s a specific win for commuters, rideshare drivers, and anyone who doesn’t want a visible cable screaming “dash cam installed.”
The second consistent praise is flexibility: power options and dual USB ports. Several reviewers mention the selector switch and the ability to run two devices. A verified buyer on Amazon called the selector “nice, and useful,” and appreciated “two usb ports.” On Best Buy, Pacman similarly said they “like extra port for second camera,” while Steven wrote that it “can run two dash cams” and described using it across “three different vehicles” and gifting it to family.
After these stories, the through-line is clear: for the right vehicle and expectations, buyers view it as a fast route to constant-power parking recording without a professional install.
- Most-cited wins: “plug and play” install, hidden wiring, dual USB ports
- Most-benefiting users: drivers avoiding hardwiring; buyers wanting a stealthy interior
Common Complaints
Price resentment is loud, specific, and repeated. Even satisfied owners often describe the cost as the primary downside, especially relative to what the device is physically. A verified buyer on Amazon summed it up bluntly: “does what it’s supposed to, pricey for what it is though.” Another Amazon reviewer went further, saying it “should be about half the price,” and joked it “probably cost less than $2 to manufacture.”
Best Buy reviews reinforce the same frustration from a different angle: buyers see it as an add-on required to unlock advertised dash cam behavior. User bstu wrote: “this should be included with the dashcam,” arguing that a camera advertising continuous capture effectively becomes “250+ turns into 300+” once this cable is added. For budget-focused buyers, the cable can feel less like an accessory and more like an extra toll.
The more serious complaint category is timer/battery behavior on specific vehicles. Digging deeper into user reports, the most alarming stories aren’t about install difficulty—they’re about the cable not shutting off as expected and draining the battery. On Best Buy, Bill reported a split experience across two vehicles: “works perfectly on the bronco but never shuts down on the hyundai and completely discharges it’s brand new battery.” On Reddit, one user described the 10-minute mode suddenly failing, leaving their dash cam “recording nonstop” for hours while parked.
There are also reports that the battery protection logic may not align with certain vehicle systems, especially those sensitive to voltage behavior. A verified buyer on Amazon cautioned: “Be careful with this with evs,” describing how voltage fluctuations and the cable’s low-voltage behavior could “slowly deplete your 12v over time.”
- Most-cited pain points: high price, timer confusion, battery drain risk on some cars
- Most-affected users: value shoppers; owners of vehicles that behave oddly on OBD power
Divisive Features
Even the timer itself—one of the headline benefits—splits opinion. Some owners experience it as reliable battery insurance. A verified buyer on Amazon said: “the shut off works well to avoid draining the battery,” positioning it as a safer alternative to hardwiring. Others interpret the same system as inconsistent or overly dependent on vehicle behavior and motion triggers. The Reddit complaint reads like the nightmare scenario for a parking-mode setup: it’s set to 10 minutes, yet it keeps going “all night.”
Build quality is another dividing line. Some users treat it as a hidden part that doesn’t need to feel premium. On Best Buy, bstu said it “feels incredibly cheap and flimsy,” though admitted it’s “something you will hide away.” On the flip side, several reviewers describe it as a reliable accessory that “just works,” like Best Buy user timco ku: “it just works,” even while wishing for more configurable delays.
Trust & Reliability
Long-term confidence is where the story gets complicated. The standout reliability complaint on Amazon comes from a buyer who said: “Mine functioned great for about two months. now i can't use it at all.” That kind of failure report hits harder because it’s not about preference—it’s about losing functionality after the return window.
Cross-referencing community chatter, the Reddit thread adds another reliability angle: behavior that changes over time. The poster described months of normal operation before the 10-minute mode apparently stopped working, leading to continuous recording sessions. That “worked fine, then didn’t” narrative is exactly what makes some buyers nervous about relying on a timer-based battery safeguard.
At the same time, there are durability-adjacent stories implying stable use across multiple vehicles. On Best Buy, Steven said they “have ran this on three different vehicles” and even gifted them to family, suggesting some users see it as dependable enough to replicate. The reliability picture, then, isn’t one unified verdict—it’s vehicle-dependent confidence with a non-zero risk of frustrating edge cases.
Alternatives
The data includes Amazon listings for third-party OBD constant power cables positioned as replacements or compatible options. The existence of these listings mirrors what some reviewers already say: if it’s “just a hidden obd cable,” a cheaper version may be tempting.
On Best Buy, timco ku framed that choice directly: “it is a bit expensive… so i would probably get a cheaper cable next time.” The implied alternative isn’t a specific brand feature comparison—it’s a value argument. For buyers who simply want OBD power and don’t care about Garmin branding, lower-cost compatible cables may feel like the rational move.
That said, some purchasers explicitly bought Garmin for perceived safety versus off-brand. In the Reddit post, the user noted they’d seen “off brand ones for like $10” but chose Garmin as “the safer bet,” which shows brand trust can be a deciding factor even when issues arise.
Price & Value
Current pricing signals “premium accessory,” and users talk about it like one. Across Amazon and Best Buy, a recurring pattern emerged: even happy owners call it overpriced, while still keeping it because it solves a specific installation pain. A verified buyer on Amazon said it “should be about half the price,” while another described it as a good solution but “pricey for what it is.”
Best Buy reviewers sharpen the value critique by comparing it to dash cam pricing. bstu called it “a steep cost for what it is,” and argued it should be included—especially with higher-end cameras that advertise parking capture. That sentiment matters for first-time dash cam buyers who assume “continuous video capture” is turnkey; user feedback suggests it may require this extra purchase.
Resale chatter in the provided data is indirect, but the market listings show the product is commonly sold new around the $50 mark, which aligns with why some buyers resent paying full retail. The most practical buying tip that emerges from community tone is to treat the first week as a monitoring period: confirm the timer behavior on your specific car before trusting it long-term, especially if you plan to use 24-hour or always-on settings.
- Value wins when: you avoid hardwiring costs/time and care about hidden wiring
- Value loses when: you resent accessory pricing or your vehicle behaves oddly on OBD power
FAQ
Q: Does the 10-minute mode reliably shut off the dash cam?
A: Conditional. Some owners say it “works well,” but others report it “never shuts down” on certain vehicles. A Reddit user described setting 10 minutes yet the camera “recording nonstop” overnight. Vehicle behavior and motion/trigger resets can affect what “10 minutes” looks like in real use.
Q: Will it drain my car battery?
A: It can, depending on vehicle and settings. Some users report the shutoff “works well to avoid draining the battery,” but Best Buy user Bill said it “completely discharges” a new battery in one vehicle. Another Best Buy reviewer warned to “watch out for drawing off your battery” if left plugged in.
Q: Is installation actually plug-and-play, or do you need a pro?
A: Most feedback describes it as truly plug-and-play. Amazon buyers repeatedly call it “super easy to install,” and Best Buy reviewers describe 15–30 minute installs with hidden wiring. One Best Buy reviewer suggested some vehicles “might require professional assistance,” but that’s not the dominant experience.
Q: Is it worth the price?
A: Only if you value a clean OBD-II install and parking mode power without hardwiring. Many satisfied buyers still call it “pricey” and say it should cost “about half.” Others argue it should be bundled with the dash cam, since it can be required for the advertised always-on/parked recording setup.
Final Verdict
Buy if you’re a driver who wants a clean OBD-II “plug and play” install with hidden wires and you’re willing to verify timer behavior on your specific vehicle during the return window. Avoid if you’ve had battery-drain issues before, drive a vehicle that’s sensitive to OBD accessories, or you need a guaranteed 10-minute shutoff with zero surprises. Pro tip from the community: as one Amazon buyer put it, the “setting button is hard to see”—double-check the switch position before assuming the cable is malfunctioning.
