Analogue extension wiring pinout

[ay_dubya]

Hi folks, noob post so apologies if not in the correct thread.

I have an Openreach 5C master socket, then a BT plug on an extension cable to an analogue phone. Cable ends at the phone are Black, Orange, Green & Red. Which two do I use, please?

[Keith_Beddoe]

@ay_dubya 

Who provides your phone service?

[ay_dubya]

Hi Keith,
It's BT.

[Keith_Beddoe]

I think you will need to specify which model of BT phone you are trying to connect up, so that you can be directed to the user manual for that phone.

If its not a BT branded phone, then you would need to locate the manual, and it should tell you which connections are needed, as those colour codes do not correspond to BT internal cabling.

You may also need to lookup the pinout for the BT431 plug. You normally only need two wires which correspond to pins 2 and 5 on bottom part of the removable section of the master socket.

[ay_dubya]

The Panasonic ST100L handset presents on a two-outlet terminal block.

[licquorice]

Use the 2 colours that terminate on the middle 2 connectors of the plug at the other end of the lead.

[ay_dubya]

OK thanks, I'll take a magnifier with me later today as I couldn't quite make them out when looking earlier.