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Wiring Diagram - 685A - WE202

Started by Lewes2, October 26, 2014, 10:32:30 AM

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Poplar1 was kind enough to direct me to the standard wiring diagram to hook up my D1/202 to a 685A subset.

Based on that diagram, I attempted to create a more easy to follow, color coded diagram seen below.  However, I know there are items missing or not correct.  Seeking your help to make it right. 

For example, at the white wire from the handset to the white terminal on the dial - - What is the ON and then a wire going to BB?  And then a green or white wire (?)

And the black wire from the handset to the B terminal on the 425 Net,  I assume that passes through the D1, but where? 

Apologize for the sloppy presentation - haven't used Visio for several years. 

Thanks in advance! 


Updated diagram incorporating Poplar1's input.


1. Add jumper wire from W on hookswitch to BB on dial
2. Move jumper from Y on hookswitch to BK on hookswitch--otherwise, you won't be able to disconnect when hanging up
3. Create a junction for the black handset wire and the black mounting cord wire. (One way is with a screw and nut, placing the two cord tips between the nut and the screw head, then insulating with black tape.)

ON=Off-normal. On WE wiring diagrams, the X is for contacts that are normally open, and the / is for normally closed contacts. On a 6A dial, the DP dial pulse contacts (Y and BK) are normally closed, except when they open and close to pulse the digit dialed. The W and BB dial contacts are normally closed, but they open during dialing to disconnect the receiver.

The wiring inside the D1 handset mounting is basically the same way for a 685A subset as for a 684A or 634A. The main difference is that the black handset wire is connected to BK on the dial for a 684A/634A, and to B on the 425-type network with a 685A. Thus a 5th conductor is used in the mounting cord. Also, the red handset and red mounting cord wires are connected to R on the dial for a 684A/634A, and to the R spare terminal [shown as part of the "line switch" in the diagram] with a 685A.
"C'est pas une restauration, c'est une rénovation."--François Martin.


Fig 1 of the quoted BSP really answers all the questions. It is arguably the easiest diagram to follow for wiring purposes, unless you are used to looking at a real circuit diagram that explains how a set works.

When starting with a historically wired 202 set, it should be recognized however, that they used to be differently wired with 684 or earlier subsets. The difference is in the use of the switches.  So there are principally two ways to wire a D1 for anti-sidetone service. The diagram in the BSP with five conductor mounting cords is a further departure from the historical wiring.  If you have a set with an original 4-wire cord, it should be wired differently yet.


Yep, I was relying on Table 1 to prepare my diagram.  I did not see the jumper David mentioned.  I also wasn't sure about that black wire from the handset to the network. 

This was rather fun. 

I made David's mods and reloaded the diagram. 

Now, I need to go down to the basement shop and see if it works!   :D



Well, it didn't entirely work. 

Ringer works fine when calling the number but I am not getting a dial tone and I  cannot call out.   Voltage at the L1 and L2 terminals on the subset strip is 49 volts but does not go down when I lift the handset off the hook.  No voltage drop.

In checking wiring against diagram, I see a possible omission.  In the official document, the R terminal on the dial has a wire but I'm not sure where it goes??  On my diagram, I am showing nothing connected to the dial R terminal.  Is this correct?

Any other thoughts?



edit - Never mind, it works fine now.  I forgot the last jumper that David mentioned. 



No, the R terminal is not used in this wiring scheme, and the official diagram actually has nothing connected either.

So that we are looking at the same diagram, here is the official version in BSP 502-320-414 Issue 1, just highlighted with the colors of the wires.

The YY mounting cord wire is indicated in blue, which could be different in a specific cord. The diagram actually indicates a six-conductor cord, but 5 is sufficient.


No wires on R of the dial. What is shown in the diagram are the off-normal (ON) contact springs which close when the dial is operated.


With the line wire disconnected, you should measure continuity from L2 to C with the phone off-hook.
That is the path from L2 through the yellow mounting cord conductor to Y, through Y and BK of the hookswitch, the jumper from BK of the hookswitch to Y on the dial, and through the dial pulse contacts to BK on the dial, through the black mounting cord connector to 2 on the terminal strip, and through the (brown) jumper to C on the network.

There should also be continuity between GN on the network and the white receiver lead, while the phone off-hook and the line disconnected.
That is from the receiver, through the wiring inside the handset to W in the handset, through the white handset cord to W on the dial, through the dial ON contact springs to BB on the dial, through the jumper from BB on the dial to W on the hookswitch, through the hookswitch to GN terminal, through the green mounting cord lead, to GN on the network.

You can also try moving the red line wire from L2 to C, which bypasses the dial pulsing contacts and the Y-BK hookswitch leads.
If there is still no dial tone, connect the handset directly to the network:
White (receiver) to GN
Black (transmitter) to B
Red (common) to R

"C'est pas une restauration, c'est une rénovation."--François Martin.


Are you sure you know what you are doing?  There are wiring diagrams in another thread that actually work!


Why are you commenting on a 6 year old post?
Harry Smith
ATCA 4434

"There is no try,
there is only
do or do not"


Here are wiring diagrams that actually work:
>edit to add link <


There is nothing wrong with this wiring diagram.