This installation covers how to install a Digitrax decoder with wires in any Athearn HO locomotive. Use either our DH123 (headlight functions only) or DH163 (headlights plus additional functions) for this installation.
*** Note: This installation is based on installing a Digitrax wired decoder in an Athearn Dash 9-44CW. The process is similar for any Digitrax mobile decoder with wires. The instructions are also easily applicable for any Athearn locomotive.
These instructions assume that you have already run the loco and have established that it is working properly before beginning installation. Remember, installing a decoder in a locomotive will not improve its performance so tune up the locomotive first.
Tools you will need:
1. Soldering iron - preferably one that is temperature controlled.
4. Small diagonal cutters for cutting and stripping small wire.
5. Tape - electrical or cellophane will do.
6. Small amount of insulated wire.
7. Drill and tap for screw (suggest 2-56 brass screws).
Now that you have gathered all of your tools, let's begin!
1. Carefully remove the shell of the loco.
2. Remove and discard the metal strip that runs across the motor from truck to truck.
3. Remove the motor from the frame by grasping it and gently rocking it back and forth. The motor is held in place by two small rubber clips that extend into the fuel tank area.
4. Turn the motor over and remove the two small copper tabs on the bottom motor strap. There is no need to remove the entire strap at this time.
5. Solder the gray wire from the decoder to the bottom motor strap.
6. Using the tape from the tools list, insulate the frame from the bottom of the motor. Place a piece of tape on the frame where the motor comes into contact.
7. While the motor is removed, select a convenient place to drill and tap the frame for a screw. This will provide better contact for the left side pick up for the motor. Solder the black wire from the decoder directly to this screw.
NOTE: If you intend to keep the foward light / mounting bracket as is, the black wire may be soldered here instead of drilling / tapping the frame.
8. Put the motor back into the frame.
9. Solder the orange wire from the decoder to the top motor strap.
10. Connect a jumper wire between the metal tabs sticking up from each truck. Solder the red wire from the decoder to this jumper.
11. Lights - For Half-wave operation - Cut the contact strip at the back of the light fixture approx. 1/4" long and solder the white / yellow decoder lead at that point.
NOTE: If you desire full wave light operation, you will need to devise a different method of mounting the light bulbs, then use the blue decoder wire for light common.
12. Track test the loco.
13. Install the headlights per the instructions in the Digitrax decoder user's manual.
14. Reassemble the locomotive.