If you can help I will vote for you... for any office... state or government! We have two separate phone lines. One for one room and one for another. One of the lines was cut off at our request by the phone company. We want to make the disconnected line active again and work on the same number as the one that has always been active. How do I determine how to rewire the phone junction box outside the house and is there a need to rewire the in house wall jack the second line is connected to? Thanks a million... votes that is... Bob

Each line has 2 conductors, or wires on 2 terminals, at phone box outside, You will need to take 2 wires and place with other 2 wires. 50/50 chance of getting it right. Connect 2 pair of wires from inside of house and other 2 wires to Telco Terminals. If your phone is dead don't worry. Just remove the pairs of you wires to other Telco Pair. If you had a picture, could explain better.
Take a cordless phone to incoming wires. Get dial tone, if you disconnect wire and you lose dial tone, you know that is active line.

Try yellow to red and black to green first. Not completely sure that is right.

Labman's right, red and green are line 1, and yellow and black are line 2. Red and yellow ,
Are Negative Voltage, and green and black are Positive, about 48 volts.
You could have unshielded twisted pair(UTP),
White/blue and blue/white pair is line 1, orange pair-line2, green pair, and brown pair.
On phone jack, white/blue to green, blue/white to red, white/orange to black, and orange/white to yellow.