The black and red wires are attached to the front and rear metal truck posts. The white wire from the decoder goes to the front headlight one side. The other side is common is attached to the blue wire that goes to the decoder The yellow wire goes from the rear light to the decoder. The other side is common (blue) and goes to the decoder. The orange wire goes from the decoder to the top of the motor and the gray goes from the deocder to the bottom of the motor. As far as I know both of the motor wires are both still attached to the motor contacts. The lights work on track voltage (unless they are wired to the engine).
Well there’s your problem - the posts on the trucks are both the same - in the stock out of the box loco, there is a long metal strap connecting both these posts with the top of the motor. The other side of the circuit comes through the frame, which is why the motor must be isolated by cutting off the tab on the bottom AND putting a thin layer of tape (Kapton tape is best for this, electricaly tape is too think and gets gooey over time, and scotch tape isn’t strong enough to resist being cut through). One of the decoder input wires must connect to th eframe - there sed to be a harness Digitrax sold that connected this wire to the light post, which is riveted to the frame but the rivet is often loose and, as in your case, the whole thing can break off. The best way to accomplish the pickup is to drill and tap a hole in the frame insie of where the shell goes and put in a brass screw, then the decoder wire can be easily soldered to the brass screw.
I forgot to tell you that I did put tape to cover the bottom contact with the motor. It is taped with masking tape as that was all I had on hand at the time. Is that ok to use?
So the post is broken off and I cannot repair it. I can drill a hole in the frame and tap it, but which wire from the decoder do I attach to it?
Also, I thought the white wire went to the front light and the yellow wire went to the rear light. And the blue wire is the common that attaches to each light on the other light contacts. What other wire is there? Does the polarity matter on a light connection?
The thing is this engine was running before I tried to install the lights. I had the white wire connected to the frame and the engine ran. It did run just a little slowly though. It is a switcher. Hope this helps.
Suprised the decoder is still OK after having the white wire wired to the frame - that is the - side for the front light, and feeding track power back in through there - yikes.
The two truck tabs should face the same way - if they are opposite one another, you have one of the trucks on backwards. That typically is the right rail, so the red wire would go there (the track power in to the decoder doesn;t really care which wire goes to which rail). The black wire goes to the frame. White is the - side for the front light, yellow is the - side for the rear light, and blue is + common to both lights. For LEDs it definitely matters which wire, white or blue, connects to the LED (and don’t forget the resistor on each LED - resistor can go on either leg of the LED). As long as you include the resistor, if the LED is hooked up to the white and blue backwards, it won;t be harmed, it just won’t light up.
I’d pick up some Kapton tape and replace the masking tape. I wouldn;t expect masking tape to hold up long term, especially if it gets any oil or grease on it - it is after all just paper with sticky stuff on the back.
I need to connect the black wire to the chassis? Right
I need to connect the red wire to one or the other of the truck posts? Right? Does any wire need to connect to the other truck connection post? You say they are on the same side and are connected. Right?
I need to connect the orange wire to the top motor connection?
I need to connect the gray wire to the bottom motor connection?
I need to connect the white wire to one side of the headlight?
I need to connect the yellow wire to one side of the rear light?
I need to connect the blue wire light to the remaining connections of each of the two lights?
Could you please verify that these are the right leads to connect to?
If only one truck post is hooked up, you get 2 wheels on the right side, and 4 wheels on the left picking up. Hook up both truck towers and you get 4 wheels on the left, 4 wheels on the right - all wheels [:D]
Sorry it has been awhile since I was talking about this.
As I am reading your email, I have the engine connected as you indicated it should be. Yes the Capton tape is on the fame below the motor.
Wires:
Gray = bottom of motor
Orange = top of motor
Red = to both truck post connections
Black = to engine frame. No engine post to connect to.
White = to headlight one side
Yellow= to rear light one side
Blue = common to other side of both lights
That is the way it is wired. But it runs with both lights on all the time in forward and I can control the engine speed. But if I switch it to reverse, it runs away at uncontrollable full speed and both lights are still on. What does that sound like to you?
Don’t forget to cycle the power. What you now describe, is correct wiring, but a previous version concerned Randy that the decoder could sustain damage.
I am (was) using a DZ126 by Digitrax. And before the wires came loose, the lights were lighting at the same time and the engine runs away at full speed in reverse. I do not know wht is causing that. I will probably replace the decoder with another of the same type.
Well, the decoder question is resolved. I have to buy a new decoder as one of the wires to the motor broke out of the decoder at the wiring entry point.
As for the lights, I am using at this point two grain of wheat or rice not sure which. I am not sure if I will be able to get them where they are supposed to go as the compartment is so small. I will have to use tape to get them in I guess.
I don’t know what the light arrangement is on an SW7 On some of my locos there is a light pipe, a clear styrene(?) bar or tube running from the headlight to the light bulb. Sometimes I cut it shorter, sometimes I have not used it at all and glue an LED behind the headlight or to a shortened light tube using the same caulk I use for track laying.
If you have to remove the LED for some reason, caulk can be pried out
If the wire broke off right after as it leaves the plug, of the harness, where the decoder plugs in, there’s no resoldering that. Nothing to solder to.
Replace the decoder along with a new harness, just the way you had it, and you should be good.