I just purchased an Athearn SD60 which was dcc quick plug ready. I took out the light board so i could install a digitraxx 165 series decoder and a digitraxx sound bug. I hooked everything up , put it back together and the front and back lights won't work . Took it back apart to check the wiring. Everything was fine. So i then switched the bulbs thinking i had somehow blown them out. Still nothing. I'm obviously doing something wrong because this very same thing happened to me before when doing the same thing to a Athearn SD40. I never did figure it out, i just use the loco in a permenant consist so i won't have to worry about it's lights. So can someone help me out ? Is it a CV value or what ? Please help.
Are the lights LEDs or incandescent bulbs? If they are LEDs, then the polarity is important, and you may have wired them backwards.
What voltage are the lights rated for? Some locomotive manufacturers use low-voltage bulbs (like 1.5 or 3 volts) and then use the light board circuit to limit the voltage, thereby giving you much more constant lighting in DC than wiring the lights directly to the track voltage. The DCC decoder generally puts out about 12 volts, which would have toasted those small bulbs pretty quickly.
Finally (and please forgive me if this sounds obvious) you have to turn headlights on with F0. People new to DCC sometimes don't realize this, and pull their hair out trying to figure out why the lights won't come on when they power up.
It takes an iron man to play with a toy iron horse.
The lights are LEDs. I thought I wired them up exactly how they were on the original light board but maybe I didn't. The reason i say that it is i wasn't aware of the polarity issue with LEDs. That could be the answer right there. By the way , the bulbs in question are stock bulbs in an athearn . When i purchased replacement bulbs at my hobby store (because i thought i had blown them) i'm pretty sure he said they were 1.5 volts. Well i'm going to go down stairs and switch the polarity and see if that does it.
I switched the polarity. No luck.
Do you have a resistor in series with the LEDs? That's necessary, too. If you don't have it, you will likely get one bright flash from each LED as it goes off to that big bright spot in the sky.
Do you still have the LEDs connected to the original light board, or did that go away when you installed the decoder? How are the LEDs wired now - through the original harness, or directly to the decoder?
Ok, i guess i don't know if the bulbs are LEDs or not. I just assumed that they were. The part number for the bulbs is ATHG63843. The bulbs are not connected to the light board. It was replaced by the decoder. The bulbs are wired directly to the decoder in the same way they were wired to the original light board. Sorry for being such a dummy but i'm terribly new at this.
MisterBeasley Do you have a resistor in series with the LEDs? That's necessary, too. If you don't have it, you will likely get one bright flash from each LED as it goes off to that big bright spot in the sky. Do you still have the LEDs connected to the original light board, or did that go away when you installed the decoder? How are the LEDs wired now - through the original harness, or directly to the decoder?
The 165 series decoders have built in current limiting and don't need resistors with LEDs.
Engineer Jeff NS Nut Visit my layout at: http://www.thebinks.com/trains/
shagspastic Ok, i guess i don't know if the bulbs are LEDs or not. I just assumed that they were. The part number for the bulbs is ATHG63843. The bulbs are not connected to the light board. It was replaced by the decoder. The bulbs are wired directly to the decoder in the same way they were wired to the original light board. Sorry for being such a dummy but i'm terribly new at this.
Which 165 decoder are you using, a DH165A0 ? Is everything else working (i.e. motor control, sound etc..) ? Did you change any CVs other than the address when you programmed it ? Here's a picture of a DH165A0.
If things still don't work, try connecting one of your bulbs/LEDs directly to the FOF connectors, hitting F0 when the locomotive is in the forward direction. Try flipping the leads if that doesn't work and let us know how you progress..
Yes ,I'm using a DH165AO . Everything else works great, i just have no lights. All CV values are at factory settings. It's address is still 0003. I'll try flipping the leads again.
Program CV8=8 just to be sure on the factory default values. Default will have the lights come on when you press F0 with no directional control.
Check here on the Digitrax page: http://www.digitrax.com/prd_mobdec_dh165a0.php
The default current limiting on the decoder is set for 15ma, not enough for the Athearn bulbs. But based on what is written on the decoder page, the other setting of 30ma is too high and the bulbs will burn out. Per the instructions, you need a low value resistor in parallel with the bulb to reducde the current - after you cut the trace on the decoder to increase the output to 30ma.
My advice - use LEDs and leave the decoder at 15ma. No resistors needed.
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.