Introduction
Maybe it was the "Total Bonding" parenting that we studied and practiced when we had our daughter. Whatever it was, when she rides in the back (rear-facing carseat) she loves to turn around to look at me. Well, she's also a gadget freak (who did she inherit that from?). She loves video screens; we have X10 cameras all over the house to keep an eye on her and she loves looking at the monitors. So I benched up this closed-circuit idea in the living room and she was nuts about it!
I had an interesting dilemma installing the screen. I needed to install it right away while she's still in the rear-facing carseat. In a couple of months, we'll be changing to a front-facing seat. At that point, I plan to mount the screen in the back of the front headrest so we can use it for videos, games, etc. But for now, I needed a way to mount it to the back of the rear seat.
My wife was adamant about a secure mount that wouldn't come off even in an abrupt stop or shock (or heaven forbid, a collision). I finally settled on a mounting bracket that attached to the top carseat latch point.
The Equipment
I found a low-cost camera and video screen at Fry's Electronics. They're not great but they do the job. The camera was $59.95 for a tiny color camera with a real lens. (Pictured below.) Smaller than a "board camera," enclosed and mounted with a bracket. It was powered by 12V so it was perfect for this application. It's got AGC so it adapts to a wide range of illumination. Its only shortcoming is that in low light levels it gets really speckled (sensor noise). Click on the images below for details.
The monitor was the second from the bottom of the line at Fry's Electronics in their auto A/V accessories section. At $179.95 it's not cheap, but cheap for a 5-inch TFT LCD. The lowest-priced monitor at Fry's ($159.95?) had tint controls so I stayed away from it. The one I got was lacking a contrast control which makes the picture a little hard to adjust, but at that price you can't be too choosy. It has brightness and a color controls.
I've reproduced the key manual pages below for specs and so you can see what the connections are like.
Mounting the Camera
I mounted the camera on the rear-view mirror mounting cowling just above where I put the Samsung hands-free microphone. I attached it temporarily with double-stick foam tape, and I hope to replace this some time with a more permanent swivel mechanism. Since it's tacked down, I had to pre-position it at an angle so it could get my face in the field of view.
Routing the Camera Wires
I ran the camera wires (along with the Samsung microphone wire) under the head panel to the upper left corner of the windshield. This is very easy to do. You just pry up a little on the edge of the head panel along the windshield and stuff the wires under. Where they come out at the rear-view mirror, I tightened a little nylon cable-tie on each of them. This provides a strain barrier that keeps it under the head panel rim.
On the driver's side of the windshield, I pulled off the cowling that runs along the corner pillar to run the wires down into the dash. It's quite easy. There are a couple of push-clamps holding it on and you can just pull it off. Start at the top. Watch out because it grabs at the front (closest to you) on a couple of metal flanges.
In a standard Prius, you have a single cable running down the length of the pillar anchored in two places by plastic mounts and tape. I covered this with 1/2" corrugated split-loom conduit (my favorite stuff) and made a break at each point where it encountered a plastic mount. Then, I ran the camera wires plus the Samsung microphone wire in the same split-loom conduit. The new wires easily make the jump between the two pieces of conduit at the mount locations. You can see an example of this in the third (rightmost) picture below. This conduit guides and protects the wires.
Where the reach the dash, I put them through a small opening in the metal substructure near the top surface of the dash. They come out above the fuse panel to the side. Then I just run them over the fuse panel and down behind the cowling immediately behind the side-view mirror-control switches. Here they reach the junction boxes.
I will cover the interconnections at the end. Before we get to that, we're now going to the back seat to see how the display is installed.
Display Installation
The "MA Audio" video screen came with a seat/headrest mounting cowling and a dash-mount ball/socket head with a metal-flange base. The first thing I did was disconnect the mounting head from the stock base. I would need this mounting head to mate with the seating groove in the back of the video screen, but I needed a different bracket to attach it to the back seat.
My objective was to anchor to the carseat/booster seat clip mounts on the top of the back deck. These are strong, metal clips anchored to the car's structural metal to securely hold a carseat. Attaching to this would insure that the video screen would not become free during an abrupt deceleration and collide with the carseat occupant. ;^>
I built it up out of standard Radio Shack car-stereo mounting brackets. The picture at the left shows the pieces from the kit that I used, and on the right is the finished bracket. (There are actually about 3x as many pieces in the actual bracket kit, FYI.)
Notice the hook in the end for the carseat clip on the back deck. Below you can see how it hooks in. I had to use a "nibbling tool" to nibble one side of the end of the long metal strap so it would be narrow enough to go through the carseat clip. It was just a little too wide. The nibbling tool nibbles off about 1/8" which was perfect. I nibbled back about 1" from the end, and then curved this into a hook.
Here are a few more views of the bracket, including the corrugated split-loom conduit (1" dia) that I used to cover the main strap. This serves to give it a better aesthetic and to guide the monitor cable from where it comes up from the seat/deck crack to where it plugs into the monitor. I used the two screws from the original dash-mouting flange with some washers to bold the original ball/socket head to the Radio Shack angle bracket. In the lower pictures, you can see the corrugated conduit with the notch cut out so it will accommodate the seat/deck flange (big black angled piece). You'll notice the irregularly cut notch in the corrugated conduit. This is because on the passenger side, the video cable comes up through the seat crack and into the corrugated conduit. I gave it a little extra space there to clear the metal flange and make its way into the conduit.
So to mount it, I slipped the hooked end of the main strap through the carseat clip on the back deck. I then inserted the flanged pieces down between the seat back and the deck. This stabilizes the mount from moving from sided to side in an angular fashion, and the friction keeps it from bouncing as the car goes over bumps.
On the left below you can see the installed bracket, complete with cable. On the right, you can see what it looks like with the monitor mounted on it.
Routing the Display Cable
The "MA Audio" display system came with a nice all-in-one cable that carried both video and power. At the monitor end, it had a mini-din in-line plug to mate to an in-line socket coming out of the display. At the head end, it had a little power junction box with an RCA video socket on it. This end went up under the dash, and the mini-din end came out between the back seat and deck to run along the mounting bracket to the back of the monitor.
To run the cable, I started at the back seat. I left enough slack to hang just a little in front of the seat, and ran it back to the seat/deck crack. I slipped it just inside the crack and ran it to the left to the driver's side edge of the seat. I then slipped it into the crack down along the edge of the seat.
At the bottom, I removed the kick panel at the base of the back door sill, and slipped the monitor cable into the space with the other cables. To secure it, I slipped it in the tight space between the metal clips for the kick panel and the door sill (on the "outside" edge of the metal clips). This secured the cable and kept it out of the way of the kick-panel mounting flanges.
In the picture on the left, you can see the door sill with the kick panel removed (and sitting right next to it). In the picture on the right, you can see zoomed-in detail of the video cable as it arcs a little between the two metal kick-panel clips. The video cable is indicated by the lables. Click on the images to get a high-res view (although without the labels).
I then ran it in a similar fashion under the front-door kick-panel, along with the other door-sill wires (including the Coastal ETech Remote Trunk Release wires). I also removed the under-dash kick-panel on the left to situate the video junction box behind the Prius wiring harnesses. See the pictures below for the general scheme
The new video and power cables go up under the dash to join the camera cable behind the side-view mirror switch. There I have a Batt/Ign/Gnd distribution to which they are all connected. There is no switch for this system; the camera comes on automatically when the car starts (running off Ignition), while the monitor has its own switch on its front panel.