Thread: Which one is the 12v wire on this reverse cam (pic inside)

No one's going to be able to tell for sure based on just the picture. It doesn't say center positive or negative on the AC adapter? Chances are you're right, but you should test it. If you don't have an multimeter, use an LED (with proper resistor) or something.

Well first off, there HAVE to be two wires, your camera would need power and ground for a complete circuit.

second, mushin is right. There is no definite standard for which wire is which; NORMALLY the center part of a connector is positive and NORMALLY the stranded/uninsulated conductor in a wire is ground, but I've seen it done the opposite way in some cases so it's never good to assume. As he said, you need to just test it. If you cut off the connector from the AC adapter as it sounds, then just plug in the AC adapter with its hacked-off wires (just don't let them touch) and use a multimeter to measure the voltage on them... of course if you have the black lead on the bare one and the red lead on the insulated one, if you get a positive voltage then the insulated is +12 and the bare is ground, if you get a negative voltage then it's the other way around.

These dont come with a ac adapter, just had a barrel plug at the end with a non standard connection size so i couldnt test it that way. I have a multimeter but without connecting the wires to some form of power thats kinda moot isnt it? I figured the auction was wrong about there being 2 wires.. This is exactly what it says

" the red power cable (plug) should be connected to a 12 V power supply, which is the voltage all standard van/car battery provides. If you don’t have the connecting head that fits our plug, you can cut the red plug from our camera and connect the exposed line directly to your car battery’s power supply, which is what I did on my car"

The exposed line makes it sound like ONE line, or the actual exposed line in the wire but he doesnt make reference at all to the red wire.

Oh, so that's the wire coming off the camera? And there's nothing describing the polarity of the plug that was on it? I'd contact the seller and grill him for more info. Otherwise you're just going to have to straight up try it and risk frying it.

no labels at all on either wire. Seller isnt responding to me.. I think i'm gonna have to bite the bullet and jsut try it for myself

It's always possible it will work either way. Don't know how likely.

In any event, I'd test the plug to find out which wire was the center pin, and try that one for 12V. Probably your best bet.