I have been working on a old electromechanical dumbwaiter that was installed around 1925 using a 120 V control line for a three phase 204V motor and have everything working but the at floor indicator ckt. The one on the 1st floor works but the upper floors do not. The bulbs are ok but no power is there. I have been looking for a wiring diagram used in that time period. Would appreciate any help available.