[PDF] Lets go over the basics of telephone wiring. Lets go over the basics of telephone wiring. Once you understand the basics, troubleshooting becomes a breeze. It may be time consuming, but a breeze. And at $40 or more for a half hour's service from the telephone repair guy, the wind will be at your back!! The really basic basics of telephone wiring.. Telephone Wiring Diagram - Ask-The-Electrician Wiring a Telephone Jack After installing the Cat 3 - 3 pair phone wire I am ready to install the wall jack. You will have a wide variety of telephone jacks to choose from but the wiring for a single line phone service will be standard.