Just a heads up. I found THREE black with pink stripe wires in the cab of my '93 XLT (4 banger with manual trannie), and not a one of them lit the test lamp. Also no wires under the console as suggested in another post. I spent a couple hours fiddle farting around with that before giving up.
Final solution ... I popped the boot off the shifter, and made a small hole in the rubber gasket underneath. Routed a reinforced wire through that and scotch blocked that to the reverse switch harness located on the drivers side of the trannie. Black with pink stripe ... kewl! Routed the other end under the carpet then up under the dash.
My accessory hot and ground were tapped off the thing that goes ding. Anybody who's had their head under the dash with the key on knows EXACTLY where that is.
PS ... Amazon special set me back less than $50. Includes the wireless senders and a clip on mirror type monitor that works surprisingly nice. Only complaint might be it's a bit weak on contrast on a bright day, but I'd think that's more the rule anyway.
Having had a similar camera fill up with water, I also put black tape on the seam on the camera itself. A bit of silicone sealant where the wire goes into the camera body as well. I'll keep my fingers crossed that helps the weatherproofing ...
** I also mounted the camera up high. Got a topper, and wanted to be able to see behind a short popup camper. Couple trim screws and some more black silicone hold it on.