All,
I have been installing quite a few decoders for a customer, my father and myself the past few weeks. The other day, I placed a Marklin 60760 kit in my father's 3102 borsig. Wiring was done cleanly and correctly, and the locomotive was running fine. The next day, after about a half hour of running the locomotive randomly stopped.

After a lot of diagnostic work, it seems the locomotive will only run forward if the headlights are off. Backwards is fine with or without lights, and forward is just fine without light but the second I turn the light function on it stops.

Any ideas on how to fix this? It is not a short.

Also, here is something I suspect to be related. I was running a smoke unit and front headlight off the same wire. (which is how it was done in analogue) Could I have overloaded something mid running around the layout after an hour's worth of sucessful usage? If so, I'd say I blew the chip but it still works with with that light off.

Help!

In my 3084, I mounted a thin strip of 0.5mm PCB on the string connection to the light/smoke unit. That way I seperated smoke and light. Remember there is an "secret" Aux output on the decoder.

EDIT with link:

https://www.marklin-user...aspx?g=posts&t=13444

BTW if there is 2 smoke generators, as I recall there was room for in the Borsig, the current is signeficant.

Buy ESU decoders. They are cheaper and have options for extra functions.
Eric

Am I correct that the decoder stops instantly at the moment you hit the light button without any load being installed? And the loc will never run if the front-light is set to 'on', even after pressing "Stop" button twice?
If that is correct, and assuming there is no short circuit within the wiring, then it is high chance that there is a defect/damage (short circuit) in the decoder's pcb itself. If you have ohm-meter, compare the output impedance from the decoder between front and rear light.
The other possibility is: corrupted firmware. But this is very rare.