When I wired mine up I just tapped into the reverse light wire. Didn't need to do any thing fancy. It should provide constant 12volts. Are you sure you tapped into the correct wire? When you are in reverse can you manually put your head unit into backup camera mode just to see if it turns on at all?

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Yes, the camera works manually. After MANY hours of trying everything in the world, I hooked the camera up and pressed the button on the head unit to turn on the camera, and it works perfectly. I have probed all of the wires at the tail light cluster, and found the only wire that triggers the reverse lights. However, the multi-meter does not read 12 volts. In fact, it was such an odd reading (and it wasn't constant), that I tested my multi-meter on several different 12 volt spots to make sure that it reads properly (battery on 2 different cars, and also a jump box battery). Like I said, I tapped the black wire with the blue stripe. I have found a bunch of information about relays on the reverse wire on this Jetta. However, I should not have to go through all of the issues of soldering up a relay to get a constant 12 volts.

 

Post pictures of how you installed the backup camera please.

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