Why Do I Hear A Landline Dial Tone On My Huawei

Without looking at it, I will give you a couple of things to check. If the phone company came out and added the second line, you should have a -50VDC across the two screws where the phone company added the second line service. You should be connecting the rear apartment phone wires to these screws. If this is the first phone line to the rear apartment, use the blue/white pair of wires. You should then have -50VDC at the phone jack in the apartment that you are adding. If you have the -50VDC, call the phone company and make sure your service has been provisioned in their switch.