There should be a diagram with the decoder, but here's one from the Digitrax website:http://www.digitrax.com/v1/ftp/ditchlights.pdf
Note that the bulbs used in this example in the pdf file are 12v bulbs while OMI uses 1.5v bulbs. The OMI bulbs need a resistor to knock down the voltage to acceptable limits, at least with the DH163 and DH123 decoders. The DH165's may or may not. I haven't done much with a DH165D yet, but some DH165's seem to have current limiting resistors built in (like the DH165AO, which is a board replacement form factor rather than shrink wrapped).
Paul A. Cutler III
wow Paul thanks for your answer.
Yes it's my first time doing this so I will have to read and re read what you wrote me. Is there any image that illustrate how to wire everything?
Thanks!
fondo,I've done more than a few OMI's, so I've been down that road before. BTW, only two of your pics show up...the third won't load.First, have you ever done a hard-wired decoder install before?
Second, do you want working headlights?Third, are there ditchlights and do you want them to work properly?
Neither decoder will help you if you want ditchlights. You need a DH163D or DH165D for that. Otherwise, the DH121D would be okay for this loco if you just want front and back headlights. The DH163IP has a plug on it, and would be worthless for this OMI engine (unless it has a plug on it for DCC...and I don't thing OMI ever did that).
When installing a decoder, the first thing to do in this case is to unplug the lighting, then remove that PCB (printed circuit board) with all the DC lighting components on it. IOW, cut all the wires leading to the board from the various lightbulbs, leaving as much wire as possible on the bulbs.
Before doing anything else, mark the underframe to indicate the forward end either with a marker, scribing it, or some tape.
Next, you have to disconnect the wires from the motor, either by cutting them or unsoldering them from the motor. You may have to pull the motor out to get at the lower soldering pad, or you could try to leave some wire on the motor for a connection later.
At this time, you should also cut the truck wires, leaving as much wire on the trucks as you can. You'll need them later. You should now have both trucks totally isolated from each other and the motor, with the motor isolated from anything else.
Get the decoder out, and you'll see it has 9 wires on it: black, red, orange, gray, blue, white, yellow, green and purple (not in that order). Black & red go to the trucks, orange and gray go to the motor, blue is the common for all lighting, white is for front headlight, yellow is for rear headlight, green is for Function 1 (or F1), and purple is for Function 2 (or F2).
The secret to doing a good hard wire DCC install is to use the least amount of wire to get the job done. Trying to save all the wire makes it a real bear to get the shell back on.
I usually position the decoder right on the motor top center and tape it in place with 3M Magic Tape as it won't dry out like normal tape will. At this point, I temporarily wire the decoder in place by merely stripping the wire of the ends of the black, red, orange and gray wires off the decoder, then connecting them to the proper wires on the model.
Red on the decoder goes to the engineer's side of the engine (or right side), black goes on the fireman's side (or left side). On your model, it appears that OMI has done the opposite, so red decoder wire to black truck wire and black decoder wire to red truck wire. You only have to do this for one truck at this time as this is only a test.
Now connect the orange and gray wires to the motor. I don't know which goes where...that's why we test first. Make sure all wire connections are not touching anything else, and bring it over to your DCC track. Put the loco on it with the track power off. Again, make sure all wire connections are isolated from each other or the model. Now turn on track power and try to run the engine on address 03. The loco should run and it should run forward as indicated on your DCC system throttle. If it runs backwards, then the motor leads need to be reversed. Which ever way it is, write it down. Either orange on top and gray on the bottom or vice versa.
Bring it back to the workbench and undo all the wire connections. At this time, cut to length the orange and gray wires so that they are just long enough to connect to the motor (if you are splicing wires together, use 1/16" heat shrink tubing). Strip 'em and connect them to the motor as indicated by your test run.
For the truck wires, stretch them towards the other truck and see if they'll connect. If so, great. If not, you'll have to add a little piece of wire to them, but don't solder them yet. Once you've got the front and rear trucks ready for solder, measure, cut, and connect the red and black decoder wires to the nearest connection to the truck wires. Now solder and insulate the wire connections.
Bring the model back to the test run area, and run it again. The engine should run forward and back, matching the direction of your DCC throttle.
Lighting is the tricky part. Each 1.5v bulb will need a resistor. I usually start with a 680 ohm, but that may be too much or too little.
Start with one bulb, and temporarily connect the blue wire to one leg and a resistor to the other leg of the bulb. Now connect the white or yellow wire to the resistor. Bring it over to the DCC test area (making sure all wire connections aren't toucing anything important) and turn on the light. If it's the brightness you want, great. Otherwise, you have to play around with different resistors until you get one you like. Back to the workbench.
What I do is pair up resistors by twisting them together at one end so they are side by side for engines like yours with twin lights (with heat shrink tubing covering the ends). One bulb wire goes to each resistor end, while the other end of the resistor goes to the blue wire. The other two bulb wires go to either the white (front) or yellow (rear) wire. You have to do this twice, once for each end of the loco. I try to put all this inside the shell, taping it all in place and leaving a long blue, white, and yellow wires so one can get the shell on and off easily.
If you have ditchlights, you have to do the same for them, but with the green and purple wires, one resistor each, plus the other connection to the blue common wire.
Again, test it on the DCC track to make sure it all works, then put the shell on. One more test, and it should all light up and run. To program the ditchlights, program CV49 to 104, CV50 to 104, CV51 to 106, CV52 to 107, CV62 to 196, and CV63 to 64. This will cause your ditch lights to be on while moving along the track and flash when you press F2 at the crossing. If you run into a specific problem, please post it. Good Luck!Paul A. Cutler III
If you run into a specific problem, please post it.
Good Luck!Paul A. Cutler III
Hello everyone, I'm doing my first steps in DCC and I would like to turn my OMI locomotive in DCC. I don't know how to do it, that's why I need you help on the procedure. I've taken photos and I do understand about electricity and using a tester. It would be greatful any comment you can give me or any web page where it explain how to do it.
It's HO scale, and I have the following decoders(if non of the are usefull, please tell me which one can be)
DH121DDH165IPPhotos
Thanks in advance! :D