Need help with Digitrax decoder and Ditch lights

Nick8564

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Sep 3, 2004
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I have a DH163P Digitrax decoder. I am hooking up ditch lights to it. Well atleast trying to. I am using 1.2mm 1.5V 30mA bulbs. I have one hooked up to fuction one and on hooked up to function 2. Both are also hooked into the blue wire in the harness (the solder pad was too small on the backside, made a mess, you would think they would make it easier, so I just spliced the blue wire in the harness. I set up my CV values like they are set up in the Digitrax Decoder manual, page 43, titled the best ditch lights or something. Well niether of them will flash. Can anyone help me. Thanks
 

Freelancer

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Oct 24, 2002
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Do they at least light up? You probably already know this, but you have to have the headlights on, and then press F2. They will only stay flashing as long as you have F2 pressed. If they don't even light up you may have burned them out, do you have any resistors installed? I have set up ditch lights on one of my units using the same CV values as on pg 43 as well. It is packed up right now, but I will pull it out and check the wiring, and the CV values as soon as I can find it.

Freelancer
 

Freelancer

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Ok, I found it. I am using a DH163D, so I am not sure how different the two decoders are. I am using 1.5V 1.2mm 15mA bulbs, I have one hooked up to function one (green wire) and the other to function two (purple wire). I have two 625 ohm 1/4 watt resistors wired between the function wires and the bulbs, then the bulbs are wired to the lamp common (blue wire). My CV values are:

CV #49= 0
CV #50= 0
CV #51= 106
CV #52= 107
CV #62= 0
CV #63= 0

It works like a charm!

You said that you made a mess of the pads on back, you may want to check to make sure that you didn't connect a couple of the pads together on accident. Also, if you left the iron on the pads for too long, you may have cooked the decoder. Just a couple of thoughts, I hope this might help. Let us know how it turns out.

Freelancer
 

Nick8564

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Sep 3, 2004
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I have a 470 ohm resistor on each power lead to the bulbs. But the light is dull. I would have thought the 470 ohm would have made it brighter. I only messed up the common solder pad, but figured it out and the other two pads are ok. The decoder works still. The lights that came on the train are LEDs and they are bright. So it makes the bulbs look really dim too. I have hooked the bulbs to a AA battery and they glow bright.
 

Freelancer

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Oct 24, 2002
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So the decoder and lights work fine? Your problem is that the lights are really dim? Did you ever get them to flash? I am not quite sure what the problem could be. I put a 560 ohm resistor on and they are pretty bright, brighter than when I hooked it up to a AA battery. What wattage is your resistor? What tolerance? I don't know if these would have any impact, I am just thinking out loud right now.

On pg 20 of the Digitrax manual it says that for a grain of rice bulb you should use 560 ohm 1/4 and for grain of wheat bulb 250 ohm 1/4 watt resistor, and that 100 is the minimum. I don't know what the difference is between a grain of rice or a grain of wheat bulb. You could try lower resistors, but you may start blowing out bulbs, or at least lower their life rating. I was hoping that someone else might have some ideas. :confused: Have you tried Digitrax tech support? They are great to work with and they are pretty quick.

Sorry I am not much help!
Freelancer