I am trying to install a DH123AT decoder into my Athearn GP38-2 but I am getting confused as to where some of the clips/wires go. Just for confirmation, the white lead slides onto the copper strip behind the headlight. Also, where do the black clip and the blue wire go? I assumed that since this was a “Solder-free installation” that there would be no soldering involved, but it seems that the blue wire must be soldered. Help would be greatly appreciated, preferably soon.
On another, better note, my HO layout-in-progress is coming along nicely. Hopefully I can get the rest of the track laid this weekend. Pictures can be seen here: http://community.webshots.com/album/109373438labwaY
Thanks in advance,
Reed
:EDIT: So I tried the locomotive with what I have, taking an educated guess as to where the balck and blue leads on the decoder should go. When I turned the power to the track on, it the command station didn’t give me wierd signals, the locomotive would go full backwards. Help?
Reed
Can anyone help me with the Digitrax Zephyr system in general? I am starting to think that the system is crazy, not my decoder. For example, when I turn the track power on, the indicator light is red instead of green. Ideas? This site is the only place for me to get info since Digitrax is closed for the weekend,
Reed
Hi Reed,
Sounds like your Zephyr system is OK to me. I’ve just installed one on my N scale layout. The track power (“system on”) light should be red, not green; the brake light is green (yeah, I know, but that’s the way they designed it.)
Are you plugging this in to an existing DC system, or is this a totally new set-Up?
Good luck.
This is an entirely new setup. Since I am not done laying the track and and have been wanting to test some of the locomotives on the track to see if there were any trouble spots. I took an old piece of flextrack (scrap) and soldered feeders onto it. Since I did this a few weeks ago before I had my Zephyr system, I only planned to use it with my DC trains. Now, when I put a DCC-equipped loco on the track (layout not test track) it doesn’t work. If I turn the throttle all the way to stop and then pust the loco onto the test piece that is hooked up the the layout track, it will go full power, either forwards or backwards, depending on how the feeders are connected to the command station. I can’t think of anything I have done wrong: The motor is entirely isolated and all the connections are correct, except for the blue and black which I do not know.
Oh well, I will just concentrate on laying track. With reverse loops, kind of, in DCC, do you have to double gap both rails on either end of the loop?
Reed
First off. Did you make sure that the motor is isolated from the frame. If you are using the AT wiring it replaces the undermotor plate but you should put a piece of electrical tape on the frame under the motor just to make sure no contact is made. beyond that, look at this link to a modelrailroader article that should assist you in proper connection of the colored wires. http://www.trains.com/Content/Dynamic/Articles/000/000/002/386vdfwa.asp
Reed;
You have to put a gap in both rails, at both ends of the reverse loop - at least four gaps - possibly more depending on your specific track plan. In addition you need a reversing module, which is attach to your system’s out put, and the isolated part of the reverse loop. The reversing module should be the ONLY thing attached to the isolated part of the reverse loop.
Read: http://www.dcctrains.com/tonystips/dccprimer/index.htm
especially section 3.
Reed:
On DC applications of Athearn locomotives, many of us toss the clip and solder jumper wires. We do not understand why anyone would go to the expense of Digitrax’s AT clips - for an unreliable connection.
The motor is isolated. Should there be resistance between the left and right rail pickups when the decoder is plugged in?
Reed
OK. Here’s what I know. After I woke up at 11:30 this morning, my dad and I began to work with my DCC “issue” and here’s what we found out. The decoder and the system are fine, however there is something funny about my Athearn hookup. Somewhere there is a short in the loco. If I disconnect all the leads except for the + and - motor connections and the blue (light common), my loco is fine. The instant I touch the right rail connectors, either one, to their appropriate connector spots there is a short when the decoder is plugged in. We got an analog loco to run, furthering our belief that the system and decoders are fine. We also checked both decoders using the Digitrax LT1 tester and they were fine. So we know that the problem has something to do with the right rail pick-up, now we just need to find out how to fix it. Any help would be appreciated. All other issues seemed to have stopped.
Reed
Have you looked to see if the tab that comes from the truck is touching.
I have never installed a decoder in a Athearn, so I am not real sure.
The first thing to do is take the loco apart and make sure nothing is touching in the frame area. From the sound of it, the frame is somehow shorting, make sure you completely iso the motor. add in some electrical tape, also, a friend paints the frame in, thus double insulating the motor/frame.
Where do you have the black wire going to? It needs to be attached to the base of the front light bracket or soldered to the frame itself. I do agree that it still sounds like a short from the motor or motor wires touching the frame somewhere. Just an idea, but also look at the wires going into the 9 pin connector. Make sure that the red didnt get bent over and is touching another wire.
Other than that, orange to motor top, grey to motor bottom, red to both trucks, black to frame, white to front lamp, yellow to rear if you are using one. Blue is a common to either or both lamps. You may have to additional colors on the harness but they are not used unless you add other lighting functions.
One more off the wall thing. Make sure that you do NOT re-install the original metal band that extended from the front truck to the rear truck. The original one clips over the top of the motor and this will cause a short. Sorry if this is obvious, but I really do not know what all you have done in the installation.
I have the motor entirely isolated. Last night I went over the entire locomotive, every connection, with a volt meter and checked for shorts. The black lead is connected to the front lamp post. Everything seems fine except the short issue. This coming weekend when I am at my dad’s house I think I will double check all the locomotive connections and see if there is anywhere the red leads could be causing a short. If it still doesn’t work, I will call Digitrax and get some live tech support.
Thanks,
Reed
Good morning, Reed.
I noticed that in your confussion of trying to make your loco run, You did not mention if you programed your decoder before you gave it a test run. Also be sure that you are feeding your tracks AC current -[15 volts AC-5 AMPS]. It sounds like your decoder is re-acting to DC voltage and this may be the reason your engine takes off like a rocket. Best of luck in solving this problem.
Don Wick
The Yardmaster
dwick@execpc.com
Boy a real stumper here. Sounds like you checked everything I can think of. Still has to be a short somewhere to the frame??? Sometimes the easiest is the hardest to find. I would doubt it with an athearn engine but heres a problem I had awhile ago with a Rivarossi E8. I had to disassemble the trucks to make a solder connection. I wasnt careful during re-assembly and I put one of the wheels in backwards. Thus resulting in a short from the wheel picking up on the wrong rail. If you can think of any possibility that a truck or wheel is in backwards maybe check that. If this is a wild goose chase, my apologies. Just trying to throw out ideas.
Just checking to see if you still have the brass from the headlight touching the front truck clip. That would cause what you are describing.
Mike Tyl
Well, I went back over the locomotive with a voltmeter looking for shorts. I looked everywhere but the loco checked out fine, even with the decoder. However, as soon as I put the loco on the tracks, the Zephyr told me there was a short. Just to make sure, I put another analog Athearn loco with the same frame onto the tracks and it ran fine. I am going to call Digitrax Saturday for customer support, By the way, does anyone know when they open on weekends? I was thinking around 10:00am should be safe.
Thanks,
Reed
Well I called Digitrax and, as it turns out, they are closed on weekends. Thankfully I don’t need them now. I went back over the loco and found that there was a short between the blue and red leads. I had soldered the blue lead onto the front lamp post because I figured that since the white lead went to the copper strip at the back of the light then the other lead must go to the other connection to the lamp, hence the post. Well, somewhere in the decoder the blue and red leads joined, thus causing a short. Well I took the blue lead off of the post and the loco ran fine. To further the confusion, I disconnected the white lead and touched the blue lead to the copper strip and the light came on. Appaerntly I will need to isolate the lamp as well if I want to control it. That, however, will not be a problem because I am going to install lamps that will light the headlights only, not the cab and these lamps will be seperate from the current lamp position.
If this post has been confusing, here’s a summary: the short was caused by, in essence, the lamp not being isolated. I have fixed everything. I also installed a decoder into a non-Athearn loco and it is running great.
Thanks to everyone for your help.
Reed
Reed,
Everyone talks about isolating the motor, especially on an Athearn, because that’s the most usual connection back to one of the rails. However, in general, ALL the decoder’s outputs should be isolated.
I’m sure someone will jump in and say yes, you can do it. They’re right, there are some ways to make non-isolated lighting functions work. But I wouldn’t recommend them to anyone until they’ve done a reasonable number of decoder installs and understand the electrical concepts involved, if even then.
HTH,
Steve