Do I need an earth?

[Suppervan21]

Just bought a wireless rear view camera for my Swift Conqueror. The cam era has two wires - one for power (I plan to use a rear light or number plate light connector) and one for earth.
However I understand from other various threads I've read that the only earth on a caravan comes from the hook up and that it can be dangerous to attach any new equipment to (e.g.) the chassis or other metalwork in the van via an earth wire.
Should I just not use the earth wire and simply wire the power wire into a lighting power cable?
Any help much appreciated.

 

[Jcloughie]

The earth that link to to van from the car is in circuit with the car battery and will be fine to use. But no need to go back to there. Within the light cluster there will be an earth for the lights. It is often white, but not necessarily. It is usually easy to find. The lights in the cluster will have individual wires, but the earth will be the one common to all of them.

The power consumption for a camera is tiny. So your idea should work. However, and this is unlikely, your car may detect an anomaly as the load for that light will be slightly more than expected. But it is so small I doubt that would happen. It also depends on how sophisticated your car is.

John

 

[Suppervan21]

Brilliant! Thanks for that. As it happens, the number plate light has a brown and a white wire so...... Power wire to the brown and earth to the white.
Nice one John. Thanks for your help.

 

[ProfJohnL]

To avoid any future misunderstandings 12Vdc systems do not utilise the terminology of Earth. The Earthing systems is a safety device for mains systems and it serves a very different purpose.

DC supplies like battery systems either use +ve and 0V or sometimes "Ground".

Incidentally in caravans all appliances should use dedicated wires for every supply function and not rely on the chassis is or any other metal cabinetry as part of the supply or return circuitry.

 

[RogerL]

To avoid any future misunderstandings 12Vdc systems do not utilise the terminology of Earth. The Earthing systems is a safety device for mains systems and it serves a very different purpose.

DC supplies like battery systems either use +ve and 0V or sometimes "Ground".

Incidentally in caravans all appliances should use dedicated wires for every supply function and not rely on the chassis is or any other metal cabinetry as part of the supply or return circuitry.

The terms "earth" and "ground" are widely used in 12v systems but used incorrectly - as said, caravans rely on return circuit cables rather than the body or chassis, unlike cars which usually rely on the body to make the return circuit.

 

[steven_wynn_uk]

You should be fine nipping into a white wire at the light cluster nearby.