What do you do to a line that orignally had a second line and is no longer in service. I would like to use it as an extension line again. What do i do?
Is the entire line (both pairs of wires) unused, or is there already one phone line and you want to add another line (with a second phone#)?
It's hard to answer that one, not knowing what you have right now. I'm assuming the wires are all still connected and they just turned the service off at the telephone office. With that thought, you will have to disconnect the wire in the outside service box (in the telco portion) and connect it to the existing phone service terminals (again, in the telco portion of the box). My next statement is not meant to come across as condescending but, from the nature of your question, you may want to engage someone familiar with that type of work or, get your telco to do it for you.
You do not have to change anything in the TELCO side.
The TELCO is only responsible for getting the lines to the jumper/plug in s on the user side. The owner of the house is responsible for all wiring in the building.
If you want to move the house wiring to the existing line you need to identify how it is/was connected.
It should have been on the now dead set of screws in the user side of the box.
Simply move the wires to the active line side in the user side of box and plug a phone in the house into the jack.
It will be another extension on the same line.
I'm assuming the owner side of the box has the rj11 connectors. Wouldn't they have to get in behind those to make the connection? After seeing your post, I went out to my box and checked. I would have to go into the telco potion of the box to make the switch. The red and green were for one line and the black and yellow for line 2.
The TELCO brings the line to the RJ11 receptacle inthe box.
How you get from the screw terminals on the user side to the RJ11 plug determines what line you are on in a multi line setup.
The receptacle may very well have used all four wires for two lines at some point.
If you move the house side lines to the correct screws and then plug in the rj11 pigtail that goes from the screw terminals to the TELCO socket you should never need to enter the TELCO side.
If you do need to enter the TELCO side it is time to call them and make them fix their wiring.
Wiring up to the test jack is telco wiring. From the test jack in, is inside (customer) wiring. If you have to get behind the test jack to switch any wiring (i.e. open the second access), you are in the telco portion of the box. If you can make any terminal connections without opening the second portion (telco) of the box, that is customer responsibility or, a charge from the phone company to make the connections for you. If you know what you are doing and have to open the telco portion of the box to make connections, you can make the connections yourself with no push back from the telco.