Hangar works #16 – Rear-view camera on trailer

We continue improving our trailer!

2 m wide, 4,75 m long and 1,8 m tall: our tailor-made trailer!

As mentioned in the previous post, you always find aspects of your vehicle, in this case our trailer, that can be improved. Mainly by adding nice accessories.

When driving a trailer the size of ours, as wide and tall as the towing vehicle, the main concern for us is the visibility. The wing mirrors still give you perfect vision, as the trailer is 2 m wide, so not wider than our SUV. But the rear-view mirror is totally blind, so we can’t see anything happening behind the trailer. It’s not only an obvious problem when you’re reversing: being blind to whatever is behind you is uncomfortable while you’re driving too. At least for us.

I started investigating about rear-view cameras suitable for a trailer or caravan. You have many options on the market. But not so many when it comes to rear-view cameras for a trailer. The main obstacle is the image transmission. It has to be wireless, as there is no reasonable way to pass a wire from the trailer to the inside of the SUV. And there the choice is dramatically reduced.

After reading many reviews, I chose the brand Auto-Vox. The reviews in Amazon and in other webs like eBay and YouTube are very positive. Their systems are P2P digital direct communication, claiming it has a much clearer image and no interference problems with Bluetooth or any other WiFi signals.

I was originally thinking about the TD2 monitor and wireless camera set. The CS2 seems to be very similar too. But both have the WiFi transmitter quite close to the camera, connected to the camera with just 1,4 m cable. This means that the transmitter will stay quite far from the SUV dashboard where the receiving monitor will be placed. Can the cable between the camera and the transmitter be extended?

The simple wiring diagram from Auto Vox. Can the cable between the camera and the power box be extended?

I decided to write to Auto-Vox and ask if there is any possibility to have a longer cable between the camera and the transmitter. And I was nicely surprised as they replied very fast and clear.

First, they recommended to buy the W7 model, as it has a better WiFi reception thanks to the antenna on the monitor. And the monitor is a little bigger with 5”, instead of the 4,3” on the other two mentioned models. The W7 has a price of 120 €, which seemed very reasonable to me, for its quality and features.

The Auto Vox W7 monitor + WiFi rear-view camera.

And second, they told me that I can extend as much as I want the length between the camera and the transmitter using standard rear-view camera’s cable extensions. Having many choices in Amazon. They just warned me to choose a 4-wires cable, as some cameras use 5-wires cables.

Standard 4-wires rear-view camera extension cable.

So, I bought a couple of extension cables of 2,5 m each.

One for the trailer, that combined with the 1,4 m length of the camera cable, will take the transmitter to the front of the trailer, much closer to the towing car, enhancing the WiFi signal.

The second one for the interior of the F-Pace, to have a discrete route for the wire inside the car too, from the monitor to the 12V socket, avoiding annoying cables hanging in front of the dashboard.

I have a clear idea of how to install and wire the rear-view camera system. But I still have a major modification to do in our trailer! And this is to get a 12V power supply for the rear-view camera. And this happens to be a relatively complicated task. Continue reading to know why!

The trailer has a standard lighting system pre-wired in the manufacturer’s kit , ready to be connected to the Jaguar’s modern 13-pins connector. But physically, the trailer’s plug has only eight pins: from 1 to 8; so missing the 9 to 13.

The image of the right shows the empty spaces for the missing pins, marked with a red cross.

What are those five missing pins for? And why are they missing? The pins 9 and 13 are supposed to give permanent 12V from the car’s battery, with 30A capacity. And the 10 and 11 give the 12V too, but only when you ignite the car, with 15A capacity. Pin 12 is a spare, so with no specific use. Using these pins, you may power your fridge, TV, and many other appliances of your caravan. And here is the reason why the connector of our trailer has not these pins: because it’s not a caravan but a much simpler trailer with no appliances. However, it’s a shame that the connector has not the thirteen pins and allow you to connect them all. This cost-reduction philosophy of the manufacturer’s lightning system was not the best for us this time!

Standard color code and pin number chart for 13-pins connectors.

The 8-pins of the trailer’s lightning system are divided in two 4-wires cables, one for each side of the trailer.

The situation implies that we must change the trailer connector and put a new one, with all thirteen pins, and rewire the trailer lightning system into it. To do so, we buy a good quality 13-pins connector for 10 €. So, it’s not an expensive item.

The 13-pins connector is not an expensive item. Better spend few more Euros and get the best quality one!

And then a 13-wires cable (23 €) and a high resistance PVC junction box (14 €), IP66 with one inlet and three outlets, all with their corresponding cable gland, to rewire the trailer lightning system and add a third cable to bring the 12V to the trailer’s rear-view camera system.

The junction box and the 13-wires cable (not all shown in this picture).

After we receive all items, the works commence!

I start working on the 13-pins connector. Apparently, it’s a simple task. But the thirteen wires of the cable are relatively thin. In fact, all the cables of the trailer’s lightning system are very thin too. I can’t imagine using the thin cables corresponding to the 9-13 and the 10-11 to connect 30A and 15A appliances respectively. No way these thin cables can stand such a high amperage! However, I pretend to connect a rear-view camera, consuming ridiculous current, so this won’t be an issue this time.

Because the cables are very thin, I decide to use wire copper crimp connectors to make the task a little bit easier. The tools needed are very simple: cutter, pliers, small screwdriver…

Few simple tools are needed.

The result is really good thanks to these crimp connectors.

The new 13-pins connector.

Despite most of the cables have the appropriate color code as per standard international specifications, some do not. To avoid errors, I decide to put cable markers with the corresponding pin number on each one. And then I work on the junction box and do the same job, but connecting the cables to a standard terminal block.

The junction box with the wires and the terminal blocks.

As final modification, I had to slightly increase the diameter of the inlet cable gland hole in the junction box, to fit a larger cable gland, because the 13 wires cable is too large for the smaller cable gland that came with the box. An easy task with the Dremel.

Now the 13-pins cable set, made of the 13-pins connector, the 13-wires cable and the junction box are ready to be installed on the trailer’s tongue!

Time to go downstairs to the garage, and work on the trailer to install everything! I know it’s going to be long and complicated at some points. So, I ask my father to help me again. Two engineers, better than just one, will always work better and faster and solve any challenge wisely! This is why I talk as “we” again, because most of the following work was achieved with the excellent help of my father.

To fix the junction box, we use as a base a stainless-steel perforated plate, bended in U-shape and riveted to the right arm of the trailer’s tongue.

Detail of the junction box, fixed to the trailer’s tongue right hand-side arm.

We do all the necessary connections to the junction box, so the lightning system works again at its best.

And we take a third 2-wires cable, connected to the 10 and 11 pins, so to the 12V given with the ignition of the towing car. We decided to use this power supply for the camera, active while the car is running, so we have a permanent image of the back of the trailer while driving. Most of the people would connect the rear-view camera power supply to the reverse light circuit, so they get the image only while reversing. But we prefer to have the camera permanently active to see at all time what’s happening behind us, as a rear-view mirror. We believe it’s a more convenient configuration.

This is how we have run the cable from the junction box to the rear-view camera. The run of the cables is marked in red color for you to have a better understanding.

We get out of the junction box with the 2-wires cable and run it parallel with the right-hand side lightning cable, getting into the right arm of the trailer’s tongue.

The route from the junction box of the 12V power supply for the camera, marked with the red line.

Both cables run inside the right hand-side arm of the tongue until the tilting axle of the platform just in front of the front wheels’ axle. Then run to the side of the platform and come back towards the front until the front right corner of the platform. There the camera power cable runs alone up inside the square steel tube to the upper part of the structure.

View of the cable’s route, below the platform.

Here you can see a couple of details under the platform. The cables are fixed with tape and nylon straps to the inside edge of the platform, to make sure they don’t fall while driving and get damaged. To do this installation, crawling under the trailer and drilling down there was necessary. Not a very pleasant job, but worthy as the result is the wisest and cleanest installation.

Crawling under the platform was not the most pleasant task…
Detail of the spot where I drill, to accesss the inside of vertical square steel tube of the canvas structure.

After climbing up inside the square steel tube, then running horizontally inside this same tube, the 2-wires cable exits the tube to reach the connection box to the camera power device.

The route is not so simple. But it’s the proper way to do it

We put a grommet where the cable gets out of the square steel tube, to avoid its sheath to get damaged by the sharp edges of the hole we drilled.

Detail of the 12V power cable exit from the square steel tube.

Once we got there, we install a simple waterproof small junction box, to put inside the camera power box. This little box is very simple, and as it’s placed in the shade inside the trailer, under the waterproof canvas, it shouldn’t make any problem.

From this box we take out the very thin power cables that connect to the transmitter. As you can see in the next picture, the transmitter is placed under the square steel bar at the very front of the trailer, and also protected in the shade and from the rain under the canvas. This is the closest we can get to the towing vehicle, having the transmitter protected from the rain and UV rays that would damage it.

View of the small junction box with the camera’s power box inside, and the transmitter.

From there the task gets simpler. Just six more drills on the metal structure to pass through the square steel bars and get to the camera at the rear of the trailer, using one of the extensions cables we purchased. All cables are protected inside rectangular plastic conduits, secured to the steel structure using double sided tape and reinforced with some rivets.

Once we’re up there, the route is much simpler.

Here are a couple of pictures of the rear-view camera before putting the canvas back on the trailer. As you can see, it’s a typical small rear-view camera, stuck to the square bar with a 3M double sided tape and secured with a screw to the steel bar.

Detail of the back screw securing the camera.

We put a small plastic cover over it to protect it from direct rain, the sun, and the water flowing backwards from the top of the canvas while driving.

The camera and its little plastic hood.

It’s quite a good camera. It’s IP68, has 5 lenses, works with only 0,1 lux and the whole system is good to work from -20ºC to 65ºC (-4ºF to 149ºF). And it has a decent 110º vision angle.

As you can see, we put the camera on the top of the trailer, below the last square bar of the canvas structure. This is quite a high position, but the choice was to put it there or very low between the plates, just 50 cm above ground. This last option was really too low, and as we’re looking for a view similar to a rear-view mirror, the upper position was clearly the very best choice.

With the canvas on, we had to cut a small square hole for the camera and its little protection hood. The result is very discrete.

The camera is quite discrete with the canvas on.

We hope that the white strap won’t bother while driving. But if it does, a simple Velcro will fix it out of the camera vision angle.

If it gets into the vision of the camera, we’ll fix this strap with a Velcro.

The works on the trailer are finished! And we have connected the 13-pins connector to the Jaguar, and everything works! The lightning system of the trailer works fine, and the camera is powered as soon as we start the engine. We are very happy and proud of the job we’ve done. It took us one day and a half of crawling under the trailer platform, drilling steel, fighting with the cables to pass them through the inside of the trailer arm and the square steel bars, etc. But all ended properly, with the classic small injuries: some scratches here and there, a little cut with the cutter in a thumb, bump on the head when hit under the trailer…

Now it’s time to do the easiest job, which is hiding the extension cable for the monitor inside the F-Pace. I’m trying my best to hide the cable running from the 12V socket to the monitor, as I hate having annoying cables hanging around in front of the dashboard. I know… I’m a little maniac and a perfectionist. I admit it. But if I’ll drive the car for hundreds of kilometers towing the trailer, so with the rear-view monitor on the dashboard, I really don’t want to have these cables hanging around.

Let’s start from the 12V power socket. I chose to use one of the two available ones at the rear console, between the rear seats.

We have two 12V sockets in the rear centre console.

When we’ll be towing the trailer, so using the rear-view camera, I will connect there the power connector of the monitor, as shown in the picture here below.

The cable is highlighted in red so you can see it better.

The extension cable is the one that will remain permanently installed and hidden inside the car. In this rear area it runs below the passenger carpet. I tried to find a better place, but as the seats of the car are electric, there is no room at all below them to pass the cable in a more discrete way. Obviously, when the monitor is not in use, its power source will not be there and the extension cable will be totally hidden below the small carpet, out of sight.

When the monitor will be connected, the cables in this back area can be partially hidden under the plastic molds of the central console, and just a little portion of the extension cable can be seen. If we have a passenger in the rear, I hope he won’t damage the cable with his shoes.

The rear route of the cable.

From the back, the route to the front of the dashboard happens to be very easy. The extension cable is hidden below the molds of the driver’s door side. The cable there is fully protected by the hard-plastic molds, so no risk of being damaged while getting in and out of the car.

Up to the dashboard, the route is perfect. The cable is hidden and fully protected.

Once on the upper part, left side of the dashboard, the route is easy again. I couldn’t insert the cable between the dashboard and the side pillar without forcing it too much, so I prefer to leave it there, a little bit pinched between the two pieces so it doesn’t move.

And as once at the windshield, the cable drops behind the dashboard, I put a simple black lanyard for an easier recovery when needed.

I put a little black lanyard to the cable connector, to pick it easier from behind the dashboard.

Unless you have a true detective eye, the only noticeable thing on the dashboard is the small black lanyard.

Once the monitor is connected, the cable is hidden between the dashboard and the windshield.

When everything is in place, and the monitor connected, the whole installation is very discrete. It’s really hard to notice the extension cable in the few zones where it’s visible.

The 5” monitor is placed just over the dashboard, fixed to the windshield via a suction cup. The soft part of the suction cup is really sticky. I don’t know which material is it, but it really gets like glued to the glass and looks like very reliable and like it won’t move at all even in the longest journeys.

The position is low enough, so the monitor does not interfere with the normal vision ahead of the car. In fact, for a driver my size, it only hides a small part of the bonnet, but not the road.

Good location for the monitor. The driver sees it and it doesn’t hide any section of your view on the road.

When the trailer is connected, and the engine is running, the 12V power installation we’ve done on the trailer immediately switches on the camera transmitter. The signal is strong enough to connect with the monitor on the dashboard. The connection doesn’t seem to hesitate or be weak in any way but totally the opposite. So, good news. It seems that this Auto Vox W7 is a really good product and works perfectly with our trailer + SUV configuration.

The image quality is good enought to see clearly what’s happening behind us.

And being honest, the image quality is good, not as good as our standard rear-view camera on the F-Pace, but at least we have a clear image of everything happening behind our trailer now.

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