I have a 55-ton 3-truck Shay, DC version.  I want to set it up for static display (no motor action needed), but hopefully with the lights on via DC voltage applied to the display track.  In an attempt to disable the motors, so far I have disconnected the orange and gray wires on pins 3 & 4 on connector J1 on the circuit board, and this did indeed result in the motors being cut off.  When I put voltage on the track now, I get the cab light and the firebox light, but no headlights.

Can anybody shed any light (no pun intended!) on how the headlights are powered?  I assume the circuit board has some kind of constant lighting circuit built into it.  Is current flow to the motor circuit required to get the headlights to come on?  Just wondering what my options here might be.  Also wondering if I disconnected the motor wires right at the motors instead (with those pin 3 & 4 wires hooked up again) if that would make any difference.

So, in summary, I'm looking for a way to get the headlights on without turning the motors and without the motor current draw, as I'm using an HO DC cab to power the track and it won't supply enough amperage to drive the motors.

Any suggestions would be appreciated.