Color Backup Monitor
Probably the most annoying feature of our
2000 Foretravel was the backup
camera system. This consisted of a black and white camera
inside the upper rear portion of the motorhome looking out through a
window in the air intake plate. The monitor was a 5 inch
white CRT mounted in the dashboard. The monitor was also used
displaying the tank level status.
In operation, the image was low contrast, not very sharp, and of a very small area. The field of view barely covered my towed car, stopping several feet behind my rig's rear bumper, and did not extend into either adjacent lane. I discovered how inadequate this was when I "dinged" the exhaust pipe while maneuvering back into a tight spot in my driveway. (I thought it would clear!) :-(
I improved the performance somewhat by adjusting several settings on the monitor. These adjustments improved the contrast and reduced the overscan of the monitor increasing the field of view about 10%. I could now see the lower part of vehicles I was passing.
The real answer was to replace both the
camera and the monitor.
I chose to use a color LCD monitor and a quality color
of the problems I had finding a suitable monitor was that it had to
a function which reverses the picture left to right, to provide an
which matches a rear view mirror. With a simple backup camera
this reversal can be done either in the camera or the
this case, the tank gauge electronic unit outputs the information in
format, so the monitor had to be the reverser.
I found a new LCD color monitor on eBay which
met all my requirements
for under $125. I decided that I would mount the new monitor
of the dash panel on an adjustable mount. I mounted a flat
on the rear of the panel where the original monitor had been.
this I mounted the swivel mount which came with the new
This allows me to aim the monitor directly toward me for best
Initially I used this setup with the old camera. It worked
the black and white camera, and even increased the field of view a
One technical problem was a spec stating the voltage input to the monitor was 12 volts maximum. As the vehicle electrical system can reach as high as 14 1/2 volts (plus spikes), I needed a voltage regulator. I was going to build one when I discovered one already mounted on the old CRT monitor. I pulled it out and used it as-is.
The next step was to replace the camera.
Another search of eBay turned up several dealers who carried a large variety of color cameras. I initially selected one with a stated field of view of 90 degrees. When it arrived I found the field of view was much less. I called the vendor who apologized and stated that the CCD in that unit had just been changed from a 1/3 inch to a 1/4 inch by the manufacturer, with no change in the lens. He suggested a submersible unit with a Sony 1/3 inch HAD CCD. This is a very high resolution unit which also has a bank of infrared LED's for vision in total darkness. He felt so badly about his inadvertent misrepresentation, he sent me this camera as an even exchange for the first one even thought it carried a price tag of almost 60 dollars more!
The camera is very well made, it is completely weatherproof, and produces an excellent image. The fact that it also works in total darkness is an added benefit. I initially made a simple bracket that clamped to the outside of the air intake grill, covering the original camera window. I had to change the connectors on the existing wiring, but did not have to add any wires.
The operation is superb! The image
is bright, sharp, and has a
very good field of view. I can see a full lane on each
My only complaint is that if I point the camera low enough to see the
bumper for backup maneuvering, I cannot see the rear of my towed
If I point the camera to almost the horizon, I cannot see the first
of feet behind the motorhome. The obvious answer is to make
There were a couple of requirements to take into consideration in the design of the camera mount. It obviously had to be able to aim the camera higher or lower. It also had to move the camera to the rear when pointing downward. The rear of the Fortravel has a bend above the engine grill which prevents the factory camera from seeing the ground immediately behind the coach. The externally mounted camera did better, but still could not see the bumper or the ground really close to the motorhome.
I designed and built a mount using a 4-bar linkage which moves the camera to the rear as it lowers the angle. In the up position the camera is tucked up under a protective cover. I mounted a gear-head motor and an additional gear reduction on the inside of the air intake grill. A linkage from the gear pushes and pulls the camera mount through the plate. A pair of limit switches stop the motor at the upper and lower ends of travel.
The linkages are all bushed with nylon to prevent wear and to provide a certain amount of friction for stability.
The appearance of the completed camera
assembly is certainly not as
"smooth" as the almost invisible original camera, but for me, the
usability far outweighs any loss in esthetics.
The addition of the motor driven mount did require two additonal wires to be able to control it from the driver's area. There are several unused wires in the overhead area of our rig above the bed. I used two of these. I found the other end of them in a wire loom on the left side of the engine compartment. Also in the engine compartment are a number of wires labeled as spares. These run to under the dashboard. This made completing the wire runs fairly easy. A switch under the dashboard controls the camera position.
This was obviously not the typical do-it-yourself project, however if you were to omit the adjustable camera mount, there is nothing here that a "handy" owner with a slight knowledge of electronics could not do himself.
The total cost of this new system (NOT including my labor) was under $300! Its performance has exceeded all my expectations. It is bright, sharp, and clearly shows everything I want to see for the type of driving I am doing.
Addendum of February 2007
Over the last several years the display of the monitor has varied with the external lighting. Sometimes it is bright and clear, and other times it is hard to get a good image. It was not too bad, but was annoying. After reading several messages about people on the Foretravel Yahoo maillist replacing their monitors with a "Super 7" TV/monitor I went on Ebay and bought one. I replaced the color monitor with this one and now see a much more consistent bright image.
I am now using the original monitor with my
computer at home as a video
monitor for when I do video capture and editing.
Dick Mason, Prescott, AZ 12/10/03