I have an AVH-P8400BH installed in a 2008 Honda Civic EX Sedan. I have a cheap backup camera installed. I have the power for the camera wired to one of the reverse lights. I also have the trigger from the Head Unit wired to that reverse light.

When I put the car in reverse, the head unit doesn't always switch to the backup camera view. I'm trying to determine if it's an issue with the Head Unit or with the camera/wiring. It seems to do it more when the car's been sitting in the sun all day, but sometimes it works after sitting and the sun and sometimes it doesn't work first thing in the morning.

Has anyone else had issues like this? Is this more likely a Head Unit issue or the camera/wiring issue?

I also have this problem. Sometimes Ill put it in reverse and the screen will go black and other times it will switch to camera view. I blame it on the $12 dollar camera I have installed.

I have mine wired differently, power to the camera is on when the radio is powered, the backup light circuit is used for the trigger. This works 100% reliably, select reverse and the picture comes up all the time. Also you can turn the camera on from the headunit regardless or reverse or not if you wanted to do that for some reason.

I thought this was how it was supposed to work but the dang instruction for the camera install didnt explain it very well. What cable from the harness hooks to the camera for power?

The one they don't give you

The first Koolertron I bought last year had a red wire embedded in the entire length of the RCA cable. For that one I plugged the RCA in to the head unit one end and connected the red to a switched positive source at the head end. At the camera end of course I plugged in the RCA, connected the red to the positive lead on the power plug that connects to the camera and connected the power plugs negative lead to a convenient chassis ground. Then I ran a separate lead from the backup light which gives + 12 when the light is on back to the head units trigger lead.

The last two Koolertrons I got did not have the red lead embedded in the RCA so you need to run TWO leads from front to back along with the RCA lead. Same concept, RCA to the Head Unit and Camera, +12 off the back up light to the radios trigger lead, second wire to run +12 from the switched lead in the head unit harness on one end to the + lead on the power plug, ground the negative lead on the power plug to the chassis somewhere close to the camera.

Now technically, the wire off the backup light is probably available in a harness at the front of the car and you could tap it up front if you manage to locate it rather than run the lead but I prefer not to cut in to the cars main harness.

I also have this problem. Sometimes Ill put it in reverse and the screen will go black and other times it will switch to camera view. I blame it on the $12 dollar camera I have installed.

When mine doesn't work it just stays on this radio screen as if nothing ever happened.

If it switches to a black screen, but you dont get a picture, when you put the vehicle in reverse, then it is a camera related issue. If it does not even switch to the back-up screen, then it is a wiring or software issue with your 8400. One thing I can suggest is to make sure you have a clean connection to the backup light circuit. Try to splice this wire into the circuit inside the vehicle. Outside the vehicle if you splice it in and don't solder/heatshrink seal the connection it may oxidize the wires and lose the connection, or create enough resistance in the connection that the radio does not see the signal.

I used those crimp splices. i just think it is a crappy camera. I believe it is a koolertron. Even when it does work the picture is very blurry. I am unwilling to run the wires again as was unbelievably hard to get all the wires hidden. That and the 120 degree weather this past summer, made this an all day event.