The complete guide
Choosing a Wireless Reversing Camera, A Practical Buyer's Guide
The problem with reversing a long vehicle
Mirrors are good at telling you where the sides of your vehicle are. They are terrible at telling you what is sitting on the ground two feet behind the bumper. That is where the low brick wall lives, the bollard, the kid's scooter, the tow hitch you are trying to line up on. Every driver has had the moment where they get out, walk around, look, get back in, and still misjudge it by half a metre.
Add a caravan or a trailer and the problem doubles. Now the rear window shows you the front wall of the van, the mirrors show you the sides of the van if you have extensions fitted, and the actual rear of your rig is completely invisible. Backing into a powered site at dusk with someone waving their arms in your mirror is not a system. It is a negotiation.
A wireless reversing camera fixes this by putting a camera where your eyes cannot go and sending the picture to a screen on your dash. The AUTO-VOX W7 does that with a 5 inch LCD monitor and a 2.4G digital link, and it is designed so that you do not need to thread a video cable through the length of the vehicle to make it work.
How a wireless reversing camera actually works
There are two halves to any kit like this. At the back, a camera with a sensor and a lens. At the front, a monitor you can see from the driver's seat. The question is how the picture gets from one to the other.
A wired system runs a long video cable, usually coaxial, from the camera to the screen. The picture is rock solid, but the install is the hard part. On a caravan or a long trailer, it is a genuine afternoon of pulling cable, and on a towed setup you need a connector at the coupling.
A wireless system sends the video over a radio link instead. Older kits used analogue signals, which were cheap but prone to snow, flicker and dropouts. The W7 uses a 2.4G digital signal, which is built to hold a stable picture while you are actually moving. That matters, because a reversing camera that freezes or drops out at the exact moment you need it is worse than no camera, since you have started to trust it.
Both halves still need power. That is the part people sometimes miss when they read the word wireless. The W7 monitor runs on 12 volts from the cigarette lighter using the supplied 3.5 metre charger line, or it can be wired into a fuse box, ACC feed, radio circuit or ignition switch. The camera takes power from the vehicle's rear wiring. The win is not that there are no wires at all. The win is that there is no long wire between the two ends.
What the specs mean in plain terms
A few numbers in the spec list tell you most of what you need to know.
The sensor is a 1/3 inch CMOS unit with a 0.1 lux rating. Lux is a measure of light. A rating of 0.1 means the camera is built to keep producing an image when there is almost nothing to work with, which is exactly the situation in an unlit driveway or a basement car park. If you only ever reverse in daylight, this matters less. Most people do not.
Video capture resolution is 720p and the display is a 5 inch LCD. For a reversing aid, that combination is the sweet spot. You are not reading number plates, you are judging distance and shape. A 5 inch screen is big enough to read with a short glance and small enough to sit on a dashboard without blocking the road.
The lens is wide angle, and the listing gives the field of view as 360 degrees. In practical terms, a wide lens is what lets you see the full width behind the vehicle rather than a narrow central strip. How much ground you see directly behind the bumper comes down to how high you mount the camera and how far you tilt it down, so plan on a little trial and error there.
The kit weighs 0.53 kg and packs at 17 x 12 x 9.5 cm. It runs on 12 volts. Colour and material are not specified by the maker, so if those matter to your install, ask before ordering.
Who it suits
Caravanners get the most out of a system like this, because the alternative is a long cable and a connector at the hitch. If you are shopping for the best caravan reversing camera for a van that you tow a few times a year, a wireless kit with its own monitor is a lot less commitment than a hard wired install.
Pickup and van owners come next. A load bed, a canopy or a cargo barrier turns the rear window into decoration. Mount the camera high at the back, tilt it down, and you have a view of the tailgate area you simply cannot get any other way.
SUV and large family car drivers benefit in car parks and on school runs, where the hazard is usually something small and low to the ground. Trailer users, horse float owners and anyone who regularly reverses a box trailer will appreciate the six selectable guideline widths, since a line set for a hatchback is useless when you are backing something twice as wide.
If you drive a small car with good visibility and a factory camera already fitted, you probably do not need this. Be honest about that.
Getting the install right
The supplier calls it a two step job, and that is roughly fair. Step one is powering the monitor. The cigarette lighter route takes minutes and is completely reversible, which is handy if you move the kit between vehicles. Hard wiring to an ignition or ACC circuit is tidier and means the screen comes on with the car.
Step two is powering the camera, and this is the decision that shapes how you use the system. Wire it to the reverse light and the camera only wakes up when you select reverse, which keeps things simple. Wire it to a constant source like a tail light, running light or number plate light and the camera is live whenever you want it, which is what you want if you are towing and would like to watch the lane behind you.
Mounting position deserves a few minutes of thought. Higher is usually better, because it gives you a downward view of the ground rather than a flat view of the horizon. Try the camera in a couple of spots with temporary tape before you commit. Check the monitor picture each time. You are looking for the bumper or tow bar just visible at the bottom edge of the frame, which gives your brain a reference point for distance.
Because the camera can be mounted front, side or upside down, the image settings matter. Mirror view flips the picture left to right so it behaves like a rear view mirror, which is what you want for reversing. Normal view suits a front or side mounted camera. Horizontal and vertical flips handle awkward mounting angles. Set these once, check them while stationary, and you are done.
Inside the cab, the suction cup mount goes on the dash or the windscreen and rotates a full 360 degrees. Clean the surface first. Position the screen where a glance catches it but where it does not sit in your forward sightline or near an airbag.
Looking after it
Not much maintenance is required, but a dirty lens is the single most common reason a reversing camera looks blurry. Wipe it with a soft damp cloth whenever you wash the vehicle, and dry it off. Skip the abrasive pads and the solvents, both of which can haze the lens permanently.
Clean the monitor screen with a dry microfibre cloth. Check the suction cup every few weeks, especially after hot weather, and re-seat it on a clean dry surface if it has gone soft. Keep the power connections dry and free of grit. If the vehicle is going into storage for a season, unplug the monitor and bring it inside.
If the picture ever gets patchy, the first things to check are the lens, the antenna position and whether a new piece of metal or cargo has gone in between the camera and the cab.
The short version
A wireless reversing camera solves a specific problem, the blind ground behind a long vehicle, and it solves it without a cable run from one end of the rig to the other. The AUTO-VOX W7 gives you a 5 inch LCD monitor, a 720p picture from a CMOS sensor with a 0.1 lux night rating, a 2.4G digital link, mirror and flip options, six guideline widths and a 360 degree suction cup mount. It runs on 12 volts and powers from a cigarette lighter if you want the simplest possible setup.
Decide early whether you want the camera live all the time or only in reverse, because that determines where you take power from. Spend a bit of time on mounting height and angle, since that is what makes the picture genuinely useful rather than just present. Then enjoy reversing without the window-down, head-out, hope-for-the-best routine.