Nope, every wire is marked on both ends & you'll get written instructions for every wire like (connect wire S3 to terminal X on the light switch and terminal Y on the taillight). The wire will be marked S3 on both ends. You'll also have a wiring diagram & drawn images of the terminals on the switches where necessary. You only need to be smart enough to know that the short end of the harness goes under the dash and the long end goes through the firewall. You'll even get new sockets for the lights and/or new contact buttons to rebuild sockets (at least I did).

Save a life, adopt a senior shelter pet.
The three main causes of blindness: Cataracts, Politics, Religion.
Name your dog Naked so you can walk Naked in the park.