What is the best way to hook up K-line operating watchman shanty on FasTrack?

[Seaboard]

After additional wiring combinations, I finally figured it out.  The way the hookup with a SEPARATE power supply differs from the above schematic is the black wire from the Shanty is hooked up not only to the common of the separate power supply, but ALSO to the UNinsulated outside rail.  This provides a complete circuit with the separate power supply. So simple yet so elusive.

[Seaboard]

I've tried several ways...none have worked yet. 

I'm operating with TMCC, so I need to use a separate power supply for the shanty between 10 and 12 volts.  The track is a constant 18 volts.

I have two isolated track sections 40" apart.  I disconnected the wires on one of the outside rails on each insulated section, and removed the metal plates that connect the two outside rails on all the track inbetween.

I hooked up the "brown" wire to the insulated rail.

I'm running the black and red wires from a separate power supply.  I tried reversing the black and red.

Nothing worked.

The only corrrect operating cycle I got out of it is when I connected the red (left) wire from the Shanty to the positive of the power supply, the black (center) wire from the Shanty to the live common outside rail. I also connected the common from the separate power supply (a CW 80 set at 10 volts) to that same outside rail. That brings the little guy out of the shanty. When I keep the two wires together but remove them from the rail, the little guy goes back into the shanty. At least I know the whole thing works.

But of course this does not result in the shanty operating when a train passes across this section of track.

What am I missing?  What is the correct way to hook this thing up using FasTrack and a separate power supply?

Here is a schematic someone provided. 

But it does not provide specifics about which common rail the brown wire is hooked up to (the insulated or live) and which is hooked to the positive power supply, the red or the black.  I assume the red.  But, in the end, this did not work in my case.  I'm wondering if there is some conductive metalic residue left under the track where I removed the metal connecting plates that is preventing the "insulated" section from being fully insulated.  My meter showed several volts coming from the insulated rail that I assume should show zero volts when nothing is connected to it but the brown wire.