I have six, K Line Heavyweight passenger cars with MDK-034 Streamlighting boards in each car. I want to run those cars with my Legacy K4 on normal command voltages. I have had three cars go dark in a week and I replaced two bulbs in each car, each time. I know these boards are wired so that there are two sets of circuits with six bulbs on each side wired in series. I think they are 2.5 volt Christmas light bulbs. I have bunches of those bulbs but I was wondering if there is a safe way to put a resistor into each circuit to lower the voltage to a lower level, yet keep the cars adequately lit? Also, what would be the best sized resistance? Also, are they really the same bulbs that are used in Christmas light strings?