Exactly... It randomly will work randomly and ususally does not. I left a meter connected constantly for a few days and never gor a 5v reading at all. Im wondering if the reverse switch isnt telling the HU to switch over?? Normally i can sit and trouble shoot but with the holidays, work and me trying to finish my sub box i havent had the time.
OK cornflakes Ive figured it out (my issue at least). The camera i'm using is not drawing enough power at start up to trigger the HU to see. So not 5-6.5 volt is coming out. Which is also why some people say you immediately need to switch to reverse to get the camera to work and I, like most wait for the car to load before I switch into gear. So instead of using the reverse light as a power source I use the yellow wire and ground in the harness that is in the rear hatch door already(see picture) I still used the 2 diode set up with one one on the yellow wire (its switch so immediately gives 12v when yo turn on the car) and the other on the power coming from the HU. Its worked flawlessly since. Ignore the wire mess i've since soldered everything and used heat shrink to seal it instead of electrical tape
Thanks for that info! It sounds like what you're saying is the yellow wire is giving out 12V at all times? If that's the case, is it necessary to still connect to the 6V out from the HU at all?
The Yellow wire is switched when you turn on the car, but constant once the car is on. The 6v wire will still need to be attached because the HU needs the camera to draw voltage from that in order to trigger the switch when you put the car in reverse. If theres no power being pulled the HU wont see the camera.
Thanks, Hemy, the yellow wire worked like a charm (any idea what that wire is for?)... Actually during the startup phase, the HU just looks for a video signal, it doesn't look for a power draw on the 6V line, so it's actually not necessary as long as your camera is sending a signal. I actually disconnected the 6V wire and the stuff with the diodes and everything works great! Much cleaner installation this way!
Good to know mine wasa finnicky when I didnt have the 6v connected. Probably because i was trying a few things at once. As far as the wire. I believe it is for the rear wiper. I did a quick visual trace and it appeared to head into that area but to be completely honest i didnt confirm anything. It would make sense since it is switched power but again not confirmed
Just wondering how / if it worked out? Just bought a 2012 II and was looking into adding a camera if it's possible.. thanks
The camera that I purchased works perfectly. It is only hooked up to the head unit and gets its power from the 6v pin, no additional power from the reverse lights or anywhere else was needed. I've had it for about 3 months now. There is a link in a post from 9/17/12 for a BMW back up camera. That is the one I used. Galaxy S2
Mine also works perfectly. I wired it up in a different manner than most. Cornflakes and I had a little discussion and its quicker, doesnt require reverse light tapping, using multiple gound cables, diodes or rectifiers and is simplified
Do you have a write up? I'd be very curious to Learn how you did it since I'm not very handy but want to do this install thanks!
2nd that, I am now having the same problem as most, and would like to simplify my wiring as well, a write up on the new wiring setup would be most appreciated!
The problem I'm having is that I have a camera and don't know how to proceed. I would love a write up.
no, I wired mine just like the original write up said, 6v from the head unit, and the other power from the reverse light tap in, it worked flawlessly for a while, but all of a sudden, it would only work if I shifted into reverse right away after turning the car on, but now, it doesnt work at all, all connections are fine, so I'm at a loss
I did go ahead and buy the 6.1 kit that goes with the Nav unit - it works for both 2012 and 2013 (referenced in another thread:Factory Connect Camera System for 2013 Toyota Prius C with 6.1" Screen | PriusChat This kit worked very well, and my SO and I spent about 4 hours doing it. For the most part plug n play. Directions that come with are for a Camry- Pruis c differences are: for 12 v and ground wires, you need either crimp pin ends, or to double over wire connection in HU - we doubled it and then put a little tape on the top to stabilize) need to remove trim above license and drill two holes to install camera (not hard at all, need a small drill bit for a pilot hole and a 3/4 inch wide wide boring bit - meant for wood, but worked just fine in this application) The wiring comes in three pieces to make routing a little easier. The result looks great!
I agree with ChinchillaGirl, I purchased and installed this kit and it was easy to install and works great.