Reverse camera installation

I am putting in a rear camera with the typical power coming from the reverse lights. Is it possible to run another power wire from somewhere (fuse box or battery, etc.) to a toggle switch that I mount in cabin and then back to tie into the same power cord with the idea that normally the camera gets power when in reverse: shows up on my HU. But if I am driving and want to see out the back camera, I hit the toggle, power gets to the camera and viola, I can see out the back while in drive.

Any problems with this?

 

After a moments thought, I am thinking that if I connect the two power cables (one from the reverse light and one from my toggle), that I will turn on my reverse light when the toggle switch is flipped on. So, I think I need a diode in place between the reverse power and the connection to the camera/toggle power so that power is not sent to the reverse camera when I hit the toggle.

make sense?

edit: I am guessing I need something like this, but the price is outrageous for a diode. The two inputs would be the reverse light power and the toggle that I would wire up to an acc switch at the dash.

 

Here is my idea:


Someone on another forum tells me my diagram should work. No need for a second diode.

 

Diode symbol is .

It should be rated at higher than the load. What is the spec on the current draw on the camera?
3 amp, 100v are cheap. Amazon.

are you using the frac harness?

 

Thank you. Whoops on the diode symbol! I am not using the FRAC harness, just had to look that up.

As for the camera, I could not find the rating on Amazon (where purchased) nor anywhere else. It seems my internet skills have caught the covid. j/k It is a small ccd, so I am guessing less than 3 amps as well.

 

You'll still need some way to tell the head unit to switch to backup camera.

 

The camera comes with a diagram that shows a wire connecting to my new head unit such that when that wire gets power, the head unit will automatically switch to the reverse camera. It seems that part is built it.

 

I’d expect the current draw to be less than 100ma steady state. If you have the camera, multimeter and battery you can measure it.

I specified 3 amp as they are better built than lower power diodes. I.e. larger diameter leads.

You can test the camera on the bench also if you have the resources. There will be a voltage drop due to the diode, but that “should” not present a problem with its operation.

 

Great idea. I guess I can just pop the hood and connect the camera to the battery with the ammeter in series and measure the current.

Thanks

 

As someone mentioned earlier, you need to account for the video trigger. I don't know what Head Unit you have, but most of the aftermarket units have a trigger wire to display video. This trigger wire is usually connected to the reverse light power line so that the head unit switches to video display mode when you shift into reverse. Some people also use the reverse light power to power the camera, but the camera should always be powered on when the ignition is on. Especially if you want to display it when not in reverse. These cams are designed to be powered on continuously and that's how the Toyota factory cams are wired as well.

If it were me, I would connect the switch circuit to the trigger wire rather than the camera power wire. See diagram below. The diode doesn't need to source much current since it's just a trigger so a 1N4001 should be fine. They are cheap. I think there are 10-packs on Amazon for 4 or 5 bucks. I would use a 2 amp fuse. That gives you plenty of power for the cam and trigger. Most cams are less than 100 milliamps.

 

Thanks. I did go ahead with my schematic. It works as expected.