Don't know what is wrong, but I hope it is clear how the ZW-L in command mode works. You program a single address, like TR #7. So TR #7 addresses the A output, #8 the B output, #9 the C output, and #10 the D output. To get voltage from the D output, you have to address #10, turn the red knob - and - move handle D. Order of address/red knob and handle is not important. The handle will only put out as much voltage as you have set by the red knob, and, conversely, no matter how much you turn the red knob, the ZW-L will only put out as much voltage as the handle allows.
Can be a bit confusing at first. Lets look at a couple scenarios, both with the ZW-L in command mode.
Scenario #1A - you want to run a TMCC/Legacy engine. Turn transformer on. Move handle to max voltage position for the output you want to use, address output from TMCC/Legacy controller, turn red knob clockwise till you get the voltage you want, address the engine, and away you go!
Scenario #1B - you want to run a post war engine using the TMCC/Legacy Controller. Turn transformer on. Move handle to max for the output you want to use. Address the output from the TMCC/Legacy controller, turn red knob clockwise to increase voltage, counterclockwise to lower voltage.
Scenario #2- you want to run a post war engine using the handle, just like a ZW. Turn transformer on. Move handle to Ovolts for the output you want to use. Address the output from the TMCC/Legacy controller, turn red knob clockwise five or six revolutions (trying to get max voltage possible), then moving the handle off 0 volts lets you control the post war engine using the handle (output voltage controlled by handle like a ZW).
Hope this helps your situation.
Edit - Thought about my explanation overnite, and thought I should attempt to help clarify, so I made up the attached diagram. Notice that within the ZW-L, there are two valves in series, one controlled by the handle, the other controlled by the TMCC/Legacy controller Red Knob. So in command mode, you have control of both valves, remembering they are in series, so the voltage you get to the track is dependent on the setting of both valves.
In conventional mode, the ZW-L itself puts the Red Knob valve in the full open position, thus the voltage to the track is only controlled by the handle valve.
Please note that this diagram is my attempt at understanding how the ZW-L works, and how it functions as us user's see it, but it is not how the electronics within the ZW-L actually work.