KB157: DZ125 - Installation Instructions

This article was last updated on Jan. 11, 2012, 9:41 a.m. | Print Article | Leave Feedback

1. Carefully remove the locomotive’s shell from the frame. Notice the orientation of the shell to the frame so that you can reinstall correctly.

The DZ125 has 6” wires that you will solder directly to the appropriate connections inside the locomotive. The smaller size allows the decoder to be easily installed in a variety of locomotives. The bare ends of the wires are wired to the motor connections, power pickup connections and the lights according to this


Avoid stressing the solder connections of the wires to the decoder board. If a connection is broken, carefully solder the wire to the board, making sure not to contact any other parts or pads where it might cause a short circuit. You are now ready to run your locomotive. The DZ125 is factory programmed to address 03.

Installation Notes:

Do not exceed the decoder’s 500mA total function output rating.

We recommend that the Blue wire, also called +Common or Lamp Common, be connected as shown. If you wish to omit the Blue wire in your installation, consult the Digitrax Decoder Manual for more information.

The head lamp should be hooked up using the Blue/+Common wire for optimal Digitrax transponding operation.

To use a function output with an inductive (coil) type load, see the Digitrax Decoder Manual for more information to avoid damage to the decoder.

See the Digitrax Decoder Manual for full details of wiring 12-16V lamps, 1.5V lamps, and LEDs. Lamps that draw more than 80 mA when running require a 22 ohm 1/4 watt resistor in series with the directional light function lead to protect the decoder.

Some locomotives employ filter capacitors for RFI suppression in the locomotive wiring. These may cause problems with Supersonic decoders and non-decoder analog operation on DCC. This capacitor should be removed for best operation.

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