Decoder installation problems

[pdlethbridge]

I just installed a digitrax 123 decoder onto my turntable and it works great Its address 3. I can shut it off as its on a switch. Today I installed a decoder into my Bachmann 2-8-0, a 123 digitrax with the plugs on each end for a quick install. I clipped the capacitor as per instructions at NCE, Digitrax, Gateway, etc. I tried the engine but nothing, no lights, no movement, no nothing. Did I bust a wire someplace or is there another problem. I tried a second decoder with the same results.

[pdlethbridge]

I tried the decoders in another engine and they still work. Worse case scenario I  would hard wire it if I have to.

[Yampa Bob]

Hi Paul
Best I can do is offer some moral support.

The 9 pin plug that goes to the decoder has a notch, so it should only plug one way, guess you already noted that, so it must be ok.

I also assume you tried the 8 pin adapter plug both ways.

Did you try to run it again without the decoder on DC power? (with the jumper plugged back in) 

[pdlethbridge]

According to the instructions that I followed here http://members.shaw.ca/sask.rail/dcc/2-8-0/index.html it should be okay

[pdlethbridge]

does anyone have a schematic of the wires for the bachmann 2-8-0? It looks like I'll have to hard wire it. The product reference here shows the wires, but they are not marked as to what color or type.

[Jim Banner]

Once in a while, a printed circuit board will have some extraneous bits of copper left on it when it is etched.  Some years ago, I ran into such a board in a Bachmann tender.  The rogue copper connected a couple of pins on the decoder socket.  As it happened, the particular pins were also connected together with the shorting plug, so there was no effect on dc operation.  However, DCC operation was affected.  That may be what has happened here and could be considered confirmed if the locomotive ran fine on dc with the shorting plug reinstalled.  My solution was exactly what you suggest - hard wiring the decoder, eliminating both the adapter board and the plugs and sockets.

As far as wire identification goes, an ohmmeter is your best friend.  The two wire plug carries power from the locomotive pickup wheels to the tender.  Your ohmmeter will tell you which pin connects to the left wheels and which to the right wheels.  You will probably have to use a fine piece of wire as a pin to connect the ohmmeter to the plug - a strand from a piece of #20 stranded wire is about the right size.  While you are checking pickup wheels, also check the ones in the tender to see which truck screw goes to the left rail and which to the right rail.

The four pin plug carries power from the decoder back to the locomotive.  Two wires go to the headlight, the other two go to the motor.  You can separate the two pairs of wires using the ohmmeter because they do not interconnect.  That is, from one motor lead to the other motor lead might be 20 ohms or so and from one lamp lead to the other lamp lead, it might be 50 ohms or so, but from either motor lead to either lamp lead, the resistance will be very high - a million ohms or more.  You can confirm which pair is the motor leads and which pair is the lamp by connecting a nine volt battery across them, again using fine wire as pins.  When the battery is connected to the motor leads, the wheels will turn.  When it is connected to the lamp leads, the head lamp will light.

I am confused by the "123 digitrax with the plugs on each end."  The DH123 has a nine pin plug on one end only and the DZ123 has no plug on the decoder itself.  But if it is the DZ123 that you are installing, consider installing it in the locomotive.  The advantage is that you need only 3 wires between the tender and the locomotive to make it work.  You need the red and black decoder wires to pick up power from the tender wheels and the yellow wire for the tender light.  You can connect the other side of the tender light to one of the wheels.  Even better, you can connect it to both wheels using a pair of diodes, one to each wheel.  Just make sure the diode cathodes (bar end) are both toward the lamp.  If there is no lamp in your tender backup light, just use a 12-16 volt grain-of-wheat bulb.

If you really want to, you can reduce the number of wires between locomotive and tender to just one.  Use just the locomotive wheels for decoder power pickup and use the tender wheels for just the backup light.  But with this scheme, you have only half as many pickup wheels serving the locomotive.  I personally prefer to use both sets of wheels to pick up for both.

[pdlethbridge]

As I installed decoders in an athearn unit, that doesn't run either. dh123's have 1 plug  but the harnesses can have 1, 2 or 1 and clips like what is used on an athearn diesel. I am becoming convinced that I might have an address problem or power conflict. I use a MRC power pack for my switch machines. I have a dh123 hooked to the turn table and its working fine. I don't have a program track so that may possibly be a problem.

[pdlethbridge]

I found a switch not in the right position so I got almost everything running. The Connie' is still dead. I'll have to get into it to check the connections. Nothing on it works.

[Yampa Bob]

I recently installed a DH123 in a Roundhouse loco, which has a 9 pin socket.

The DH 123 sheet states "ready to run on address 03". (two digit address). Is this the same as the single digit "3" on my EZ Command?

I followed the instructions on page 5 of the EZC manual, using a programming track. It seems to be working ok on new address of "5", but the decoder instructions says to change CV01.

All my other locos are factory equipped, my first experience installing a decoder.  Am I missing something here?

[pdlethbridge]

No, but I am.

[Jim Banner]

The DH 123 sheet states "ready to run on address 03". (two digit address). Is this the same as the single digit "3" on my EZ Command?

Yes.

I followed the instructions on page 5 of the EZC manual, using a programming track. It seems to be working ok on new address of "5", but the decoder instructions says to change CV01.

That is exactly what you did by following the directions on page 5.  The buttons you pushed triggered a sequence of commands within your E-Z Command and they changed CV01 in the decoder to a value of 5.  And you didn't have to worry about scary things like CVs, programing modes, etc.

I recently installed a DH123 in a Roundhouse loco, which has a 9 pin socket.

The DH 123 sheet states "ready to run on address 03". (two digit address).  Am I missing something here?

Yes - the complications of using a more comprehensive command station.  The more a command station can do, the more you have to learn to make it do it.

[Jim Banner]

The Connie' is still dead... Nothing on it works.

Still dead on dc with the dummy plug reinstalled or still dead only on DCC?

[pdlethbridge]

both ways, I got a new tender coming. I can use a 9 volt battery to check the engine.

[Yampa Bob]

Thanks Jim
At first I thought about just trying to run the loco on address 3, but then I thought it would be prudent to use the instructions on page 5 with a programming track, in case the decoder was installed incorrectly.  Better safe than sorry.

I had a suspicion that the sequence might be changing the CV, but am relieved to have it confirmed.  The more I use the EZ Command the more I like it.  I especially like the one button transfer of control from one loco to another. 

Why don't the manufacturers follow the color convention in tenders for the wires leading to the loco,  orange / gray and white / blue?  How hard is that?

[pdlethbridge]

It makes sense and is logical. The exact reasons why it won't be done.