Help I'm lost

[AndyJB]

I've re-posted this from the Thomas forum as I'm beginning to think Thomas DCC conversions are not that common.
OK so Toby is sitting naked on the workbench, I've removed his shell and his PC board. I'm left with 4 wires which my Digitrax SDH164D Sound FX decoder instructions tell me to attach to the wires on the 9 pin "track, motor and function harness".
That all appears easy but nowhere do the instructions tell me what to do with the 6 wires coming from the 10 pin "sound harness". 2 are already connected to the speaker and 2 to the storage capacitor. All it says in regards to the sound harness is IF (and I'm not) using an external synchro cam to connect it to the white wire.
So am I to assume there are only 4 wires to hook up? It seems too easy.
Any help is appreciated.

[Jerrys HO]

scroll down to page 19 it looks like you are using 7 wires the other's are for other functions and additional lights.
I have  not installed a sound decoder yet but the schematics look self explanatory.
Others may chime in with more knowledge on this but I read the instructions and that is what it seems like to me.

http://www.digitrax.com/static/apps/cms/media/documents/documentation/decodermanual.pdf

Jerry