If you purchase the OEM kit the kit is 100% complete with all the wires you need , to include the wires with the proper pins to plug into the radios C1 connector.
As far as " where do they connect to the truck " only 3 places other than the radio .
One wire spliced to the bottom of the PDC ( +12vdc output from the Parkview fuse)
Another to an existing ground bolt near the PDC via a ring terminal .
Another wire for the line bus CBC3 located @ socket #45 in the C-5 connector on the BCM . C-5 connector is labeled " E " on the BCM . This wire also has the proper pin installed like the radio for a simple plug n play .
Other than that , everything else is attached to the kits components ie new tailgate handle with camera , supplied harness inside the tailgate and supplied harness attaching the tailgate harness to the long body harness and the supplied long body harness . The body harness connects to the PDC , ground near PDC and the BCM'S C-5 connector , aditionally the body harness also connects to the supplied 3 wire radio harness that's supplied as well .
There's a maximum of two wires to splice / solder . One @ the fuse in the PDC and possibly @ the BCM if the socket # 45 of the C-5 connector if it's already populated , some trucks & likely yours will not be populated , in that case you'd simply plug this wire in just like @ the radio.
This kit is really simple to install and in your case could be done without splicing any wires if you used a add a wire type 10 amp fuse in the PDC and the C-5 connector really isn't populated .
You can purchase the kit @ your dealer for about $260.00 , you can sometimes find it for about $220 elsewhere .
I'd try to work a deal with the Svc manger @ your local dealer to get the XAC code Flash for FREE , if you purchase the kit from them .
You can see the complete install instructions @ post #10 here by Mpgrimm2 he has a link for the install to the radio . Here's his post #10 .
https://tapatalk.com/shareLink?url=...&share_tid=53505&share_fid=17770&share_type=t
Installing OEM backup cam
Hope this helps !