145 Gateman light is dim unless I lower output on different ZW post

[ADCX Rob]

I can guarantee you didn't follow the wiring diagram exactly...  you can't use both C & D on your gateman. Use "D" only for both the light and the solenoid. The problem you are having is that C is referencing "D" instead of "U" for the return circuit on the bulb, which results in your exact symptom.

[lionelsoni]

o  What ZW do you have, a real postwar ZW or the modern one?

o  What AWG wire are you using?

o  Didn't you mean "volts" where you wrote "watts"?

[Bob Paris]

I figured out my error.  Of the three leads from the shack, one goes to power, one to ground and the other to the insulated ground rail.  All good now.  I also noted my error stating watts instead of volts and misleading title of post.  

[Bob Paris]

Building layout with ZW.  Post A for track power, B for 022 fixed voltage plugs, C for lights and D for accessories.  Main wires for these circuits and a ground wire run underneath & around the layout so I can feed off of them. I made insulated curve tracks to initiate operation of the 145 gateman and wired the accessory per the instructions on page 69 - Fig 10-6 of Greenberg's "Wiring Your Lionel Layout" so that the shack's light would be on all the time and the gateman action would be initiated when the train enters the insulated block.  For power I am feeding off of the wires from post C [lights] and D [accessories.] both set on the ZW at 14 watts.  When turning on the transformer, I noticed that the gateman shack's light was dim although the gateman action worked fine when the train passed.  I happened to reduce the power for post C to zero and the shack's light got brighter - if I raise the power from 14 [shack light is dim] to 16 watts the shack light goes out.  What am I doing wrong?  Thank you for your suggestions.