# SD70 flashing ditch lights



## dawinter (Jan 2, 2008)

I haven't found any instructions regarding turning off the alternating flash on the SD70 ditch lights. These lights should run "on steady" all the time or they would simply drive the crew crazy. And me. I never see that in 1:1 scale. Irritating as all get out. Any help here? Thanks. 
Dave


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## NTCGRR (Jan 2, 2008)

Dave 
Different RRs have different rules on that , I have seen them flash going through town here at grade crosssings. 
other than that ,sorry ,I can't help on the wiring.


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## dawinter (Jan 2, 2008)

Your right. I just saw a short video that featured a flashing ditch light in the city. No cities up this way though. I really do expect there is a way to disconnect or jumper the board to make both lights stay on all the time.


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## fred j (Jan 12, 2011)

I also have only seen them flashing as they come thru Town.

Fred


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## Paul Burch (Jan 2, 2008)

Dave,
Do they go steady at higher speeds? I think they are only supposed to flash at lower speeds,so the only way to stop it would be to kill the flasher circuit or rewire the ditch lights. What kind of control system are you using?


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## dawinter (Jan 2, 2008)

Yes. They both come on steady at high speed. Much higher speed than I normally run them in doors. I'd say scale 50 - 60 mph. I'm keep mine at 30 for the layout. That looks better. 

I'm only using DC track power right now because I'm at the end of the building and scenery phase. After that (in the fall perhaps) I'll be investing in a radio control system. Very likely AirWire with drop in boards and Phoenix sound because I only run USAT power. 

I'm not sure that a DCC type system would control these. Perhaps applying full power to the rail (about 14 volts for my purposes) and therefore the lights, and variable power to the motors, is possible with an upgraded system Don't know that for sure.


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## Paul Burch (Jan 2, 2008)

Dave,
I also use Airwire. What I have been doing for ditchlights on all my locos that use them is to use a Train Control Systems FL4 decoder to control them. I have them set to flash for 10 seconds when I blow the horn and then go steady again. They can also be turned on/off at any time from one of the function keys. The decoders are only about $17.00. A big improvement over the stock USA or Aristo ditch lights.


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## dawinter (Jan 2, 2008)

Great idea! And cheap too. (The part I like best.) Thanks.


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## Paul Burch (Jan 2, 2008)

Dave ,
The FL4's are great little DCC decoders. They actually have four programable outputs and I think about eight or so diferent light functions. You will use two outputs for the ditch lights which still leaves two to play with. Roof beacon,cab lights, etc:


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## dawinter (Jan 2, 2008)

Thanks Paul. I've has some small experience with these but I never thought of using them just for lights.


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## Dick413 (Jan 7, 2008)

with the new dropin's the ditchlights flash when crossing horn is blown


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## DKRickman (Mar 25, 2008)

Are you asking about prototype practice? 

Ditch lights (or a Mars light, though I've never seen one on anything modern) are required for any locomotive operating over a public highway crossing at grade in excess of 20 mph. The engineer has the ability to turn the ditch lights on and off, sometimes with the headlight switch, and sometimes with a separate switch. On some railroads (UP comes to mind) the ditch lights do not flash. On others (NS, for example) the lights flash for 30 seconds when the horn is blown. They will flash even when the ditch lights are turned off. 

Here's an interesting little tidbit for the uber-prototypical modelers out there. When meeting a train, it is required to dim the headlights and (on those engines which do not do so automatically with dimming the lights) turn off the ditch lights. However, since the lights will flash for 30 seconds even when turned off, you will sometimes see two trains meeting near a crossing where the engineer has flipped the switch for the ditch lights to flash on the rear of the lead unit temporarily. I have no idea if such a thing is possible with DCC, but it would impress any engineer friends you may have!


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