This engine's tender is pretty small, despite the totally incredible "23,000 gal" marking on the back of the tender. To have room for a speaker and a mobile sound decoder I think I'm going to have to wire the decoder directly to the tender connectors, and bypass the Bachmann circuit board. Haven't been able to find a wiring diagram on the Bachmann site. Does anyone have a diagram or photo delineating which wires are which in the two pin and four pin connectors?
I assume this means I'll have to wire appropriate resistors in line with the headlight and backup light wires - not sure of the size: would 330 ohm 1/4 watt be OK?
Does anyone know what the two small inductors are for on the Bachmann PCB?
Remove the DC adapter or decoder. Get the Tsunami and cut back the shrink. Remove the 9 pin connector with the wires on it. Get the 9 pin to 8 pin adapter. Plug in the decoder to the PC board. Install the speaker. Tuck the capacitor in somewhere. You can shorten those wires also if need be.
You can also shorten the wires and solder them to the 8 pin plug.
There is room. Others have done it.
The recommended decoder and speaker in the below link.
http://www.soundtraxx.com/choose/step3.php?t=ho&s=Bachmann
The below link has info on using the Tsunami. Click on Curriculum and then SoundTraxx.
http://www.mrdccu.com/
Below is a link from a Google search for bachmann spectrum tsunami install.
He was told to use a light steam but SoundTraxx recommends medium steam. Your choice.
http://www.garbo.org/MRR/2-8-0con.html
Store the links in Favorites as you will need them.
Rich
If you ever fall over in public, pick yourself up and say “sorry it’s been a while since I inhabited a body.” And just walk away.
Be aware, Bachmann does not use the NMRA recommended wire colors. Get a multimeter and use the resistance scale to ring out the wires. Follow the NMRA wiring standard for DCC installs.
Bachmann has had 12 volt light bulbs in their 2-8-0 in the beginning. Don't know if yours has LED or light bulb.
If you keep the PC board, not an issue.
Also, be aware if you change tenders, they wiring “might” not be compatible. I and others have found this out.
LED Resistor Values in case you remove the PC board which I do not recommend
Measured with 12.2 VDC supply using 20 ma max current LED's. Values will vary a ittle depending on actual DC supply value.
Resistor Current
1000 ohm 9.0ma
750 ohm 12.45ma
680 ohm 13.12ma
510 ohm 16.25ma
> richg1998 said:> Be aware, Bachmann does not use the NMRA recommended wire colors. Boy howdy! It sounds like they don't even follow a standard practice from one locomotive to the next.> Get a multimeter and use the resistance scale to ring out the wires. Follow the NMRA wiring standard for DCC installs.I have a multimeter - but all the wires from the plug to the PCB fractured at the solder joints after just a few moves testing the fit with an NMRA plug and the Soundtraxx LC series decoder, so I do not have a clue on how to determine what wire from the orange tender plug corresponds to what pin at the NMRA plug, other than that the 2-pin plug seems to be the power pickup leads from the locomotive. That leads me to believe that the remaining wires at the 4 pin plug (2 red, 2 black) are the motor leads and the headlight leads. Bachmann's catalog picture of the PCB does not show the bottom side where the wires from the 4 pin plug are soldered to the PCB, and I do not know if I can rely on the 4-pin plug to PCB relationship shown for those wires in the exploded parts list drawing.Any ideas how to distinguish headlight from motor, and how to determine the correct polarity, without disassembling the locomotive? If anyone has a 2-10-0 PCB and could photograph the bottom side connections that would be a big help.The LC decoders are older and relatively large, and the Decapod tender has limited vertical clearance made even tighter by the bottom of the coal bin, especially with a decent sized 28mm speaker in the tender floor, so I really think I need to hard wire the decoder to the tender plugs. I've considered using a male-female NMRA plug pair with the female plug wired to the tender plug and installed in the coal bin bottom, so the male plug from the decoder could be plugged in from underneath. And all with plenty of slack in the wiring > Bachmann has had 12 volt light bulbs in their 2-8-0 in the beginning. Don't know if yours has LED or light bulb.My 2-10-0 has a bulb for the tender backup light, and I presume a bulb for the headlight as well. There appear to be no resistors in line with them, but there are diodes on the PCB that seem to be across the lamp leads. Any suggestions as to how to duplicate this when wiring the decoder without the PC board?> If you keep the PC board, not an issue.Not an option for space reasons, and especially not without a wiring diagram given the fatigue fractured PCB wiring.> Also, be aware if you change tenders, they wiring “might” not be compatible. I and others have found this out.I suspected as much after reviewing the differences between the 2-8-0, 2-10-0, and 2-10-2. Too bad; I'd like to have a larger tender, like from the 2-8-0, for my Decapod to give me a bit more speaker room. I'm also considering installing the LC decoder in the much larger 2-10-2 tender, moving the 2-10-2's Bachmann (Digitrax? who?) decoder to the 2-8-0 and adding a sound bug or such to the Consolidation, and then finding the smallest motor and sound decoder I can for the 2-10-0's tiny tender and direct wiring that into it. Any suggestions would be greatly appreciated. Thanks for the resistor table and the links in the prior message.
The below site references a Digitrax part number whichis the 8 pin to 9 pin adapter. You mention Digitrax in your reply.
You can do the same with the Bachmann decoder. Remove the plug and solder it to the decoder wires.
I have the LC decoder and Tsunami decoders. They are the same size.
He puts the speaker under the coal load and drills tiny holes up through the coal load. Many do this. Glue some styrene in the speaker area for a tighter it ti isolate the sound waves from the front and rear of the speaker.
I ring out the wires with a multimeter in mine and document where they go. The NMRA has standard wiring specs for decoders.
If the loco runs in the opposite direction from what you select, just reverse to two motor wires.
The diodes on the PC board are for contant lighting. I think four diodes for headlight only, six for headlight and tender light.
SInce you might have not looked it up.
right rail, decoder red
left rail, decoder black
motor plus, decoder orange
motor minus, decoder gray.
headlight, decoder white
tender light, decoder yellow
Light common, decoder blue
Also, all decoder wirs come with detailed instructions from what I have seen so far.
To determine motor plus, but loco on track with the power pack in forward, loco goes forward and clip meter to motor terminals. That way you determine motor plus and minus. That assumes proper track connection.
You can do the same with a nine volt battery and a couple clip leads.
My opinion, much easier that direct wiring as I have done two Spectrum's with direct wiring. I have the 4-4-0 and 4-6-0, DCC ready and those are real tiny tenders compared to the 2-8-0 and 2-10-0 tenders.
I have no idea on the decoder size of the Sound Bug. I am quite sure you can find the decoder size at their site.
This is over a year later, and don't know if you ever got the answer I thought you were looking for. I was just browsing the web for an answer to Bachmann's wiring in the 2-10-2, so I took one apart farther than I wanted just to answer the question.
FYI, I always remove all the Bachmann tender circuitry, so I DO need to know which wire is which in the harness, but I had forgotten since my last conversion. This is for the HO 2-10-2 non-sound only. I can't vouch for other models or the sound version.
Two-pin plug is Rail Right (black wire) and Rail Left (red wire)
The 4-pin plug is:
Motor + (brown wire)
LED + (yellow)
LED - (orange)
Motor - (red)
Milt
If the Bachmann factory in China is still using the same color coding, the wires are as follows:
2 pin plug: Power feed from locomotive's wheels to tender -- Red = Left rail pickup; Black = right rail pickup.
4 pin plug: Yellow = Headlight LED PLUS side; Orange = Headlight LED NEGATIVE lead; Brown = Motor Positive lead; Red = Motor Negative lead.