I installed a Digitrax decoder on an Athearn blue box engine. I had two 12 volts bulbs wired in it before BD (before decoder). After I installed the decoder the motor turns fine but the lights don't work. I wired one lead to the white wire and the other blue. I wired one lead of the other light to the yellow wire and the other lead again to the blue. Is this incorrect? I am running a NCE system but tried the unit on a regular DC track before DCC. I then tired DCC and still no light.
If the lights don't work I have some 4 volts bulbs but need to add a resistor to. What size of resistor do I need? Thanks in advance.
Did you turn on the lights?
Sometimes, people who are new to DCC don't realize that the lights don't come on when you power up. F0 should turn the lights on. On some decoders, you also have to start the engine in motion before the lights come on, but all the Digitrax decoders I've installed don't work that way.
Your wiring sound correct. I would use 16-volt bulbs if you prefer incandescents, but as long as you're in there you will be better off with LEDs and a 1K resistor. For Transition Era and earlier, get Golden White or Yellow LEDs, which have a "warmer" glow to them. I personally like bright headlights, but if they seem too bright you can use a larger resistor which will dim them down a bit.
I think most decoders put 12 volts on the headlight lines, so your original bulbs should work. They will, however, eventually burn out when run at their rated voltage. Using 16-volt bulbs will give them longer life, but they won't be as bright. Using LEDs will give you bright lights that will still be working when you're pushing up daisies.
It takes an iron man to play with a toy iron horse.
You did run the wires to the bulbs, and not to the old post, right? If you have blue and white to one bulb and yellow and blue to the other, there should be nothign else touchign the bulbs except those two wires on each.
Also try resetting the decoder, set CV8=8. Do NOT use the PowerCab's decoder recovery menu option, it's only for NCE decoders. Sometimes even noew out of the package decoders have some odd settings left over from factory testing.
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
does the DH123 come with the light outputs set for LED's and not bulbs?? i have read something somewhere about bulbs and LED's but that may have been to do with board replacemnets rather than plug in decoders.
A DH123 is a very simple decoder. Motor control and headlights is all you get. The voltage on the headlight lines is about 12 volts DC, and I don't think you can adjust it or set it for LEDs.
Nope, DH123 is a basic simple decoder, 2 functions (or 4, they snuck 2 more in at some point), all at essentially track voltage. No included resistors or current limiters like the fancier decoders.
Hi
I also have a problem with a digitrax SDH164D sound FX decoder with no working lights, installed into a Bachmann baldwin 4-6-0 steam loco and use the F0 function and loco plays a sound instead of headlight comng on . Loco runs well but sound is not that good (makes some sounds without pressing function buttons.)
-andy
Another thing to check is the current draw of those 12v bulbs. I think the DH123's function outputs are rated at 125ma each. Even if the bulbs are properly isolated and wired, you could still blow the outputs if they draw more current than that.