Hello Community,
I am trying to do a digital conversion of my 30-year diesel loco Märklin 3072 as shown here.
I noticed in the post the person who did the conversion was able to make the train change LED light colors based on direction. Here is a similar post.
I would like to set it up the same way white lights forward rear tails lights in the back and switch based on direction, but don’t how and what parts I need.
Can anyone give insight on this ?
I will be installing a Motor Märklin 60944

Here is a picture of the train and the interior.

Hi
Thank you for your comments

1. The red lights are on AUX 1 and AUX 2 respectively. So are independent from the white lights. How they are working is a mater of function mapping.
My mapping is as follows
F1 = AUX 1: (reverse) + AUX 2: (forward). Both negative logic.
That means: when the loco start the Red lights go on according to the direction of movement independent from the front/rear lights.
If we want the reds of just activate F1. (No red glow when there are wagons connected).
The mapping can change according to your taste

By the way what controller do you have?

2. The 60976 has exactly the same base plate. The U+ is the white.
My color code is a bit strange. I basically use Märklin expect for AUX 1 and AUX 2 I used NEM (AUX1=green, AUX2=violet) because the Märklin wires are to thick.

3. Yes they are. In some cases I used SMD with a piece of light fiber in the front.

4. Yes always the resistor is on the cathode, except in some cases (swiss light changeover) where I need special behavior of the LEDs.

Always do the drilling on the plastic housings by hand and not with a power drill (damage on the plastic) or with a drill at very low revs. I do the drilling manually.

The cables of the Märklin decoder plate are too thick for the space of this loco. So better to use ESU cables at least for the frond and rear lighting.

regards

Costas

Hello Costas,
Thank you for the feedback, after doing some research on what you've described and the parts you used, I seem to have a better understanding :

1. I eventually will need to upgrade to a CS3 for better function mapping and customization, but for now if I want to make it work on my 6021 using the f0 function, can I connect it as so ?:

Front (Gray cable): 3 front White LED's and 2 back Red LED
On the Back (Yellow cable): 3 Rear White LED's and 2 front Red LED.
So as long as the F0 is ON: 3 front whites are ON and 2 rear Red's are ON, when I reverse direction 3 Rear Whites are ON and 2 Front Red's are ON

The wiring would look something like this:



2. So for the SMD LED's I see how you connected them to a vero board, (thank you BigDaddyNZ for the pic). I also noticed you had a similar approach in this conversion HERE. I will use SMD's instead if DIP LED's, but could not find a SMD 1205 (only 1206).

3. And last thing I noticed you used 2 inductors (E516520) on position I1, I2 but I don't where/how the're installed on the diagram.

Awaiting your response,