# Digitrax DZ123 headlight does not respond to F0



## Dennis461 (Jan 5, 2018)

How do I turn off the headlight, DZ123. It is on in FORWARD, off in REVERSE. I'd like to turn it off at will.
I am using Decoderpro, have tried many settings on the two 'screens' for lighting.

I can get it go program OFF constantly, work normally but cannot turn it off with throttle.
I've sent Digitrax the question (and got a useless answer). Anyone have an idea?


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## CTValleyRR (Jul 26, 2014)

Not all decoders allow independent control of lighting. Check the manual for yours.


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## J.Albert1949 (Feb 3, 2018)

Is this an engine with BOTH a forward light and a rear light?
You didn't tell us.

You have decoder pro?
How about getting decoder pro set up with this engine/decoder, and then...

take a screenshot of the "function" pane
take a screenshot of the "lights" pane
... and post them here?


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## Aqualungs (Jan 25, 2021)

Did you setup the FX3?









Sent from my SM-G998U using Tapatalk


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## Dennis461 (Jan 5, 2018)

I have other decoders.
Most are using the default values, except for address and speed tables.
My Digitrax SDH166D, (in my Bachmann F7B loco) the F0 function behaves as expected.
I can turn the headlight off. (It may actually be a taillight I forgot which end is front)
My Athearn F7A has these following tables DZ123 matching my SDH166D.

[ Update, I just tried a DZ146, F0 turned off the headlight as expected.]


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## J.Albert1949 (Feb 3, 2018)

The headlight settings in the post above look proper to me.
This is for the "F0" function (I have zero experience with pushbutton controllers, does "F0" equate to a button called "headlight"?).

This will turn the F end light on in forward, and the R end light on in reverse.

I prefer to do it differently, as I like to control the F end and R end lights completely "independent of one another".

How I would do this (looking at the images above):

UNcheck Forward Headlight and Reverse Headlight (white & yellow, respectively)
For function 1, check "white"
For function 2, check "yellow"
Then, down below you will have to "search the popups" and set function 1 behavior to "on both directions" (if there's a setting for that).
Also set it in function 2.

Now, each headlight should be able to be turned on or off, regardless of which direction the engine is moving. That's the way it works on "the big engines".

Don't be afraid to experiment.
If things don't go right, just reset the decoder (set CV8 to "8") and start over...


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## Dennis461 (Jan 5, 2018)

Hmmm,
Experiment? I've been doing that for days

The DZ126 does not have F1 or F2 wires, so that menu in DecoderPro may not be applicable.
My Athearn F7A (with the DZ126) is currently in a consist as a non-leading unit, so the throttle uses F1 f=and F2 for sound features in the B unit.

Later today, I'll de-consist the F7A and play around, but I'm starting to think Digitrax fouled up their design.


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## Dennis461 (Jan 5, 2018)

Well, I am getting closer to understanding this problem.
When I remove the F7A from the consist (set CV19 to 0). I have headlight control.
So I next went to this tab in decoderpro.
There are only two options here, so I picked 'Respond to Consist Address', but still no headlight control for the engine as a trailing unit.

More experimenting to do.
I've been scratching my head so much, I forgot why I wanted to turn off the headlight 😩


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