Hello All, I am replacing the blown MRC decoder in my n scale Athearn Challenger. I am temporarilly installing a DZ123 Digitrax decoder til I can afford a Tsunami. I am having trouble with the front light which blew when the decoder shorted out due to poor factory wiring. I replaced the light and can not control the light. It stays on constant. I checked the DZ125 and found it malfucntioned with the front light on constant. I installed a known good decoder and still have the same problem. It appears that the front light is wired 1/2 waved only needing the white wire to operate but it stays on constant. I thought it was as simple as adding a resistor to the white wire but that has not been the case. I have had the motor wires hooked up as well as the rear light which works fine and the engine will run fine. Can anyone help resolve this issue? I hope to publish the finally install somewhere to help others as I have been unable to find a published install for this engine.
Steve
Hey Martin, the front light was and still is an incondesent bulb. There are only 5 wires from tender to locomotive, track pivkup are the two outer most wires, the center wire is for the front light function, and the two wires on either side of center are the motor wires. Now there is a ciruit board inside the locomotive. On the light circuit, there is two diodes which I am unsure of the purpose other that light control in DC mode. I have seen a post somewhere talking of Phil Perry having a how to put a Tsunami in this but I have been unable to find this article by him. I imagine it would be a simular application just to put a DZ125 in this wonderful piece of equipment. I am not sure how to send pictures through the forum, I will send you pics via your email so you can see. I am pretty sure you are the Martin I know personally.