onetouch

Hello everyone, I have a backup camera i would like to connect to my head unit. Question should the power to the camera be from a constant +12v or should it be powered from the reverse (lamp) +12v? thanx for any help

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NotYou

Either is acceptable -- well, I take that back. You either want to attach it to the reverse lamp 12volt supply, or the accessory 12volt. Don't wire it to a constant 12volt supply, as it will drain your battery when the car is parked.

As to which to do, it depends on when you want to use the camera:

- If you want to only see the rear view camera when backing up, or if your head unit switches automatically to the rear view camera when the camera is powered on, then you want to attach it to the reverse lamp.

- If you want to be able to use the rear view camera while driving and when backing up, and you can switch to the rear view camera manually (i.e. button on the head unit), then power it to the accessory 12 volt source. Note that this way will not automatically switch to the rear view.

pancit175

NotYou is almost completely correct.
It also depends on the screen. Weather the screen automatically detects the camera when the signal is on, or if it uses a dedicated input wire to the reverse wire. If the screen does not have a reverse wire input, then NotYou is absolutely correct.
Also it may depend on the camera. Some cameras take a 1-3 sec to fully engage itself after power is given to it. Usually I like to give the camera acc power. That way there isnt as much of a delay after switching to it. But there may be a few things left to do if you don't have a reverse wire input.
When powering the camera to acc, the [releatively] easiest way to wire up the camera to a screen that uses signal sense is to interrupt the signal line with a relay, using a switch and the reverse wire, diode isolated from each other, to activate the signal.

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