2-4-4-2 Articulated - Connection Pinout?

[tbdanny]

Hi all,

I'm in the process of converting one of the Bachmann 2-4-4-2s into a tank engine, and as part of this, I'll need to wire in a new decoder.  However, I'm unable to find a wiring diagram on the Internet.

The model has two plugs - a two pin plug on the right, and a four pin plug on the left.  Can someone please tell me which pin is for which function?

[Flare]

If you remove the board in the tender, you may find its wires are marked on the other side.

I don't have an articulated, but my other Bachmann On30 locos have been this way.

[dutchbuilder]

I did the same with a 2-6-6-2.
As you are not going to use the tender forget that wiring.
You will have to do some reverse engineering on the wiring in the locomotive.
It shouldn't be that complicated because you only have six wires.
The standard wire colours from a decoder are black and red for the wheels, orange and grey for the motor and white and blue for the
head light .
You will have to do some measuring because Mr. B is colour blind and not always uses those colours.

Ton

[tbdanny]

Right.  Time to break out the multimeter, then.

[dutchbuilder]

Yep.
Don't forget to place a resistor between the decoder and the + for the LED headlight otherwise you release the magic smoke.

Ton

[tbdanny]

Ton,

No worries.  I usually use a 1K resistor.

As for the pinout, I checked it earlier this evening.  I was able to remove the circuit board from the tender and untangle the wires.  From this, I was able to map the pins on the connectors to the functions, and double-checked them with my multimeter.  The two-pin plug is the power pickup from the driving wheels.  As for the four-pin plug, the pins are as per below:

[dutchbuilder]

It's been a while since i remodelled my articulated but you are absolutely correct.

Ton

[tbdanny]

Was that the 2-6-6-2 you linked to on that other thread?  That looked fantastic.

[dutchbuilder]

Yes it was.

Ton

[Kernow]

The two-pin plug is the power pickup from the driving wheels. 

Apologies for reviving an old thread but the connector wires on the 2-4-4-2 tender I have are all black.

Did you work out the correct polarities for the 2 pin plug ?

Thanks

[RailMan63]

Interesting. Is the plug wiring the same on the 4-6-0 as it is for this one?
Thanks!

[Ton N]

The two-pin plug is the power pickup from the driving wheels. 

Apologies for reviving an old thread but the connector wires on the 2-4-4-2 tender I have are all black.

Did you work out the correct polarities for the 2 pin plug ?

Thanks

Doesn't matter, if you measure the voltage on the track you will discover that the multimeter thinks it's AC.

Ton

[Kernow]

Doesn't matter, if you measure the voltage on the track you will discover that the multimeter thinks it's AC.

Ton

Wrong. It does matter.

The track power feed from the locomotive to the tender is from the left rail via the left side driving wheels and vice versa for right rail track power. The tender wheel pickups likewise pick up power from both tracks, left side wheels from left side rail and vice versa.

The left rail feeds from both the loco and tender are combined where they are soldered to the DCC motherboard. Same for the right side. This provides track power from both rails to the DCC decoder.

So if you get the track power connection from loco to tender wrong the result will be a short circuit.

So yes it does matter.

If you don't believe me cut off the power cord from a domestic appliance, then strip back some insulation from the cut end of the two power wires. Plug the cable into your household power and touch the bare wires together to see that AC power can be short circuited if you get the connections wrong.   

And I already know that DCC track power is AC and I don't need a multimeter to prove that fact.

https://en.wikipedia.org/wiki/Short_circuit