DD40 Lighting Query

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Smudge617

Well-Known Member
As you can see I've finally got round to installing the new motors in my DD40, I'm upgrading it to LED's too but I don't know how the loco would be lit, are both headlamps lit going forward and a red at the rear? and when reversing is the light at the rear lit, if so what colour I'm assuming white, and which headlamp(s) would be lit at the cab end when in reverse and would they also be red?

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I've just got the decoder wiring and light's to do tomorrow, and then it's done, Oh! don't suppose anyone knows where I can get Number board numbers from, just noticed their aren't any on this.

Thanks.

I can hear my bed calling, so I'll say G'nite.😴
 

bnsf971

Gomez Addams
Staff member
If you want to light it the way model manufacturers do these days, you would wire the lights and program the decoder so the front lights are on when going forward, and the rear lights are lit going backward. Older Athearn models didn't have a dedicated light for the nose light, so you have to decide whether to carry on the tradition, or upgrade.
If you want the engine to have lights as the real ones, you will need to wire and program the lights for what is called rule 17 lighting. The lights would still be wired the same way, you will just need to program them to follow the way the real ones work, rather than how model makers make them work.
 

Smudge617

Well-Known Member
If you want to light it the way model manufacturers do these days, you would wire the lights and program the decoder so the front lights are on when going forward, and the rear lights are lit going backward. Older Athearn models didn't have a dedicated light for the nose light, so you have to decide whether to carry on the tradition, or upgrade.
If you want the engine to have lights as the real ones, you will need to wire and program the lights for what is called rule 17 lighting. The lights would still be wired the same way, you will just need to program them to follow the way the real ones work, rather than how model makers make them work.
Thanks, but what is rule 17 lighting?
 

Smudge617

Well-Known Member
The rule 17 toggling with most decoders is pretty up front and easy, i.e. click a box if ya want it.
For rule 17 I have change CV's 49 & 50 on mine, I have a few loco's I need to programme, so it's been added to the "To-Do" queue.

Overall, I'm quite happy with this, I also added a cab light, but as this is only a 4 function decoder, it's on with the headlight.

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D&J RailRoad

Professor of HO
I think that was a feature for the DC days of trains, so you knew which direction the loco was going.
In the prototype world, headlight usually stays on either direction.
 

Smudge617

Well-Known Member
I think that was a feature for the DC days of trains, so you knew which direction the loco was going.
In the prototype world, headlight usually stays on either direction.
Yeah, I noticed that all DC loco's the headlight stays on regardless of direction, can't really turn them off unless you add a reed switch or something similar to one.
 

Smudge617

Well-Known Member
I might have had some diodes in mine so the headlight would be directional.
I'm not much good with anything electrical, I'm one of those that knows what I know, and what I don't know, either ask, or get someone else to do it for me.(usually the latter)

I tried to follow the thread about UTP's, but got lost after the second paragraph 😂
 

D&J RailRoad

Professor of HO
a diode is an amazing little thing. It's nothing more than a little cylinder with wire sticking out of each end.
A diode only allows electracy to pass through it in one direction.
When ya put it in line with a battery and a light bulb you can see how it works.
Oriented one way, the light bulb will glow as it should. Turn the diode around and the light bulb won't get any electricity.
With a DC locomotive, electricity will pass through the motor in one direction or the other, depending on which direction you want the loco to move.
 

Smudge617

Well-Known Member
a diode is an amazing little thing. It's nothing more than a little cylinder with wire sticking out of each end.
A diode only allows electracy to pass through it in one direction.
When ya put it in line with a battery and a light bulb you can see how it works.
Oriented one way, the light bulb will glow as it should. Turn the diode around and the light bulb won't get any electricity.
With a DC locomotive, electricity will pass through the motor in one direction or the other, depending on which direction you want the loco to move.
I've only a few DC loco's left, most I've converted to DCC as I've found, for some reason the older version's run better.
 

kjd

Go make something!
With a four function decoder, I would have one as the headlight, the next as the other headlight, another as a rear light and last as a cab light. Often on locomotives with two "headlights" one is a standard headlight, on steady to light the way and warn of the train's impending presence. The other was usually a warning light of some sort, usually a gyralight or a mars light. DRGW had a mars light in the nose and steady light between the numberboards. SP had the headlight in the nose and gyralight up on the cab.
 

Smudge617

Well-Known Member
With a four function decoder, I would have one as the headlight, the next as the other headlight, another as a rear light and last as a cab light. Often on locomotives with two "headlights" one is a standard headlight, on steady to light the way and warn of the train's impending presence. The other was usually a warning light of some sort, usually a gyralight or a mars light. DRGW had a mars light in the nose and steady light between the numberboards. SP had the headlight in the nose and gyralight up on the cab.
Thanks.
 

otiscnj

Well-Known Member
Not adding any flywheels? This looks like one of the 70's versions, no flywheels, and the motors mechanically connected.
 




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