Jim and Jeff

Thank you for your reply and patience.  Both were of great assist.

Mike

Folks I most certainly appreciate your returns, however, the issue is that the lamp is lying on the frame sandwhiched between to two halves, and the frame is showing continuity between both halves. This is the first time i have taken the unit apart and could not understand that dilemma. i.e. my question as to how we obtain a difference of potential to complete the circuit for the lamp.
Do i have to insulate both halves ( which appears so ) if yes can you recommend how? had Bachmann neglected to insulate?

much appreciated...Mike

On a Bachmann Highroller (N Gauge), with regards to the headlight!  how does the incandescent bulb obtain a voltage difference of potential allowing it to light.   The bulb appears to be sandwiched between the half's of the locomotive body.  The bodies are insulated from each other, but yet the bulb lies between both halves.
Be easy on the new guy

Thanks in advance Mikel