where to wire power for backup camera?

Hello,

I recently had my DNX 9960 head unit stolen out of my truck.  I had a generic backup camera mounted in the rear bumper which was left.  This was all installed by a local stereo shop.  I have decided to save money, I will do the install myself this time around.  All of it makes perfect sense and the wires for most functions were left so I can match up the colors just fine.  However, the only exception is the power lead from the rear camera.  The stereo shop ran a red wire along with the vide lead all the way from the rear bumper to the dash area behind the head unit.  Which wire can I tie the power wire from the camera into?  I don't want to use constant power as I want it to shut off when the truck is off, but does the accessory lead provide enough power for the camera?  They had it hooked to one of those wires back there,  just trying to determine which one.  There is no relay so I am sure they didn't use constant and accessory to charge a coil and provide 12v to the camera from the constant.  Any suggestions?

ED7

The back light goes to the camera which then joins to the wire leading to a wire on your head unit possibly pink.

The purple wire on my head unit goes to the reverse light wire...i got that much.  The red wire which comes from the camera, however, is the 12v power wire.  I am wondering which wire I can hook that up to behind my head unit that has enough power to run the camera?  I would have thought that the stereo shop would have hooked the camera power lead to something in the rear of the truck, but they ran the lead all the way up to the radio, but i am just unsure of how to wire it so its only on when the truck is on?

hi, not many trucks have an easily accessible switched power source at the rear...exceptions would be ones with a seven pin trailer connector, and then not all of them. the red lead coming off your head unit should be the switched power lead. you can power the camera from there...camera should draw much less than an amp of current. it wouldn't hurt to fuse that lead (someplace accessible) as cameras do often fail and external wiring is more easily damaged. if the fuse blows, the radio should remain working. a one amp fuse would be fine. mark

Thanks for the info.  I will wire it to the accessory power wire that feeds the radio.