Speaker connections on TSC 21-HWM 21 pin connectors

Richard Sutcliffe

I am installing a 21pin sound decoder in a P2K RDC

I have a a TCS 21-HWM connector that has solder pads for adding wires. There are 9 pads are nicely labled with NMRA colours on the pin side, and 3 none tined pads on the other side. These 3 pads are not labled.
I need to find the connections for the speaker, and am curious about the third pad.
I haven’t found any detail on these 3 pads on the TCS website.

Dick Sutcliffe
General Manager
Bradley, Roger & Tidewater Rwy.
Cariboo Traction Company