I have the V140 Diesel from the Märklin 37203 DGR Forefathers set and in the process of converting it from factory digital to sound using a Märklin 60946 sound decoder. The LED panels located at each end have 3 wires in the normal Märklin lighting colors of gray (front),yellow (rear) and orange. Each panel contains 5 surface mounted LED's, 2 white ones and 3 red ones with the white lit in the direction of travel and the red showing to the rear.

Since I had 2 of each color, I wired the two gray together and soldered them to correct pad and likewise the two yellow together to the correct pad. When testing the engine all the LED's show red when in reverse and the engine will move in reverse. When placed in the forward position the engine will not move and the two lower LED's flicker rapidly on and off.

I remove the LED panels and attempted to find out how the wiring works. When I place + voltage on the orange wire and - on the yellow wire the 2 lower red LED will light. Any other combination produces no response.

Any ideas on how the panels should be wired using this decoder or a way to check them to see if they are working correctly would be appreciated.

Thanks, Chuck

[img][/img]

[img][/img]

[img][/img]

Hi Ross, No, I used a 3 volt DC power supply to test them. From my experience, when LED are damaged they will no longer work at all.

Since my original post, I have since rewired the V140 using the factory decoder that originally was installed and they all work fine. I'm thinking that this decoder is specially designed with circuitry for using these LED panels. Not being able to reverse engineer the decoder, I'm thinking that in order to have the LED work correctly, maybe you need two power sources feeding the LEDs to have the white lights work. I was only using one 3v power source.

I have decided to leave well enough alone for now. At least I was able to successfully convert the motor to ball bearings.

Chuck