Basic wiring help please!

Hi Everyone,

Can somebody with some wiring knowledge please have a look over this basic diagram and tell me if my thinking is correct.

I am installing a reversing camera as normal but two questions:

I want to have a switch in the cab that I can flick on when I am driving forward to check what's behind me, ie the load I am towing or the trailer hitch, is this possible?

Can I use the existing power feed of the interior light to tap into for power of the screen?

I don't have any experience in doing this sort of thing myself but want to give it a go!

This is the type of system that I have:
4.3" Inch TFT Car LCD Rear View Rearview DVD Mirror Monitor + Backup Camera Cam | eBay

Any advice welcome!

i fitted one of these to our motorhome, i took a live from the stereo, and had a switch so it was on all the time when i was driving. it wont take you long to fit

Did you just wire a switch direct to the mirror monitor or to the camera?

wired correctly with a diode (one way electrical gate) so you don't back feed the rev lights you can fit an override switch so it will switch on reverse or on switch via ign feed

Mac90 said:

I want to have a switch in the cab that I can flick on when I am driving forward to check what's behind me, ie the load I am towing or the trailer hitch, is this possible?

Click to expand...

Yes, this is possible, but not with your circuit.

Mac90 said:

Can I use the existing power feed of the interior light to tap into for power of the screen?

Click to expand...

You can, but I really wouldn't recommend it. The interior light uses a permanent live. Running from this will keep your camera powered permanently, so will drain your battery overnight and you'll be jump-starting every day.

All of these types of rear view camera things are the same circuit wise. The camera and the display are two separate devices, each requiring their own power. You want the display to be powered when you’re driving (i.e. when ignition is on). However, the camera only needs to be powered when, either, you are reversing (in which case you would take the camera power feed from the reverse light), or in your case, when you switch your magic switch on the dash (which makes it ever so slightly more complicated).

Your display should be powered from an ignition live. So you will have to run a new wire up to your mirror for its power. Either spice into a solid dark green wire (that is a dark green wire with no other trace colour) from your fuse box (these should be fused ign) or from a solid white wire (un-fused ign) if you’re going to install an inline fuse.

For your camera, you need to install a single pole double throw (SPDT) switch in your dash (AKA an on-on switch). From the common terminal of the switch, run a wire to the positive power wire of your camera. From one of the throws of the switch, run a wire to your reverse light positive. From the other throw, run a wire to your fused ign live that you used to power your display. All earths are earth, just connect them to your chassis/body work or another earth (solid black) wire. All of this is two additional wires from the front to the rear of the vehicle in addition to your AV cable.

The magic switch will allow you to switch between; the camera only being on when you are reversing, or always being on when you are driving (allowing you to check that your trailer is still there). Whilst your ignition is off, so is the camera and display.

Regarding your circuit, Fanatic is right, you would be back feeding your reverse light. It will be on all the time your dash switch is on.

Can't open pic if I could I could help :-/

https://picasaweb.google.com/107952874506609645671/Landy?authuser=0&authkey=Gv1sRgCKPPiNK6xdiTZg&feat=directlink

This is a wiring diagram, do you think it will work?