# Bachmann Rail Bus program lights to always be on



## Tom_C (Jan 8, 2016)

I just got a Bachmann Rail Bus and am waiting for a Tam Valley Shuttle controller, that as far as I know does not control lights.

I want to program the rail bus so the lights (currently function 10) come on automatically.

Is that possible, and how? I have a NCE Power Cab that I can use to program it.


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## wvgca (Jan 21, 2013)

as far as I remember, cv's 49 and 50 control the front / rear lights, I don't think there is a constant full brightness, but you can set them for both on dimmed, with a value there of 44, and the brightness can be adjusted in cv 61, this I think was for TCS decoders, not all brands may follow this though..


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## Mark R. (Jan 26, 2013)

You could remove the function wire from the lights and attach it to either rail (track input) for constant on - although you wouldn't be able to turn them off aside from shutting off the track power. 

The lights will get half wave power from the rails, so you may have to add or adjust the resistor if using LEDs or low voltage bulbs.

As for changing the decoder to make a function output do something different ? .... can't be done on those decoders. They are a VERY basic decoder and cannot be reconfigured, or re-mapped for that matter. They are what they are. If you want to alter how the functions operate, you are going to have to replace the Bachmann decoder with one more capable of re-configuring.

Mark.


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## Tom_C (Jan 8, 2016)

Thank you both for the help. I am technically inclined but a beginner to DCC and only use my trains for the holidays.

The lights are turned on with F10 and can be dimmed by half with F1. There are interior, headlights, and marker lights and they are controlled together.

Mark, below is the info I have found for the decoder. I think the lights are probably all tied to pin 6, is that a good guess? I can tie pin 6 to pin 8 for constant on?

http://www.bachmanntrains.com/home-usa/ez_content/1_Amp_Decoder_Instr.pdf

http://www.bachmanntrains.com/home-usa/images/44913_Decoder_IS.pdf


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## Brakeman Jake (Mar 8, 2009)

I would try giving both CV 33 & 34 a value of 3.You'd still have to manually turn your lights on upon starting your train but they should stay on all the time whether going forward or reverse.

Be aware!!!....I've noticed that the Bachmann Easy Command decoder uses a 1-8 bit numbering while other decoders use a 0-7 range.If you are to tinker with CV programming,this offset is to be accounted with,it may create confusion.


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## DonR (Oct 18, 2012)

As Mark suggested, for always on
lights in a DCC loco, you should totally disconnect
the lights you want to stay on from the decoder. Create
a bridge rectifier with a limiting resistor if you
have LED lights, and connect it to the wires from the
left and right rail. If you have incandescent bulbs
you would only need the resistor to match the 14 or
so track volts.

The circuit described is how I light my passenger
cars and cabooses. Always on.

Don


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## Tom_C (Jan 8, 2016)

Thanks everyone for the help. As it turns out, the shuttle controller turns the lights on... it seems a bit arbitrary and I'm not sure it's by design because sometimes the lights come on immediately and sometimes they come on after several cycles, but they always come on within about 5 minutes.

So, I can live with that, and I don't have to either test various CVs or hack the light wiring.


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## CTValleyRR (Jul 26, 2014)

Tom_C said:


> Thanks everyone for the help. As it turns out, the shuttle controller turns the lights on... it seems a bit arbitrary and I'm not sure it's by design because sometimes the lights come on immediately and sometimes they come on after several cycles, but they always come on within about 5 minutes.
> 
> So, I can live with that, and I don't have to either test various CVs or hack the light wiring.


I've been using Tam Valley Depot products for about 8 years, and I doubt anything is arbitrary.

I would e-mail Duncan McCree at TVD and ask him. His e-mail is on their web site.


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## Tom_C (Jan 8, 2016)

You're probably right, and I did send a question but I'm sure he's very busy this time of year.

I suppose it takes several cycles to blast out the light command for the various loco addresses, and in any case I'm happy that the lights do come on in a short time, so I'm happy.


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## Tom_C (Jan 8, 2016)

Received a message from Duncan, and it is indeed by design. He said it should turn the lights on immediately, but if it doesn't you can power cycle the device and it should pick it up on the next power-on. I'm fine waiting the few minutes until it eventually lights up.

Also, FYI, for anyone reading this, you can have multiple mid-points using the Tam Valley shuttle controller, as long as there is sufficient time between mid-points.


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