Eurostar dummy car lighting problem

[Smudge617]

Hi

I'm retrofitting a Eurostar with directional lighting. Apart from messing up the soldering on the original board of the power car and having to fit a lighting board instead, all has gone well

My problem lies in the dummy car, I've fitted the pickups, done the wiring, wired up the decoder as per the manufacturer (Laisdcc) and nothing, I've checked I have power and the correct resistors, and also the LEDs aren't blown, but it wont light up at all, I've also checked the decoder and all is as it should be. I might also point out I swapped the decoder for a brand new Zimo and had the same result, any ideas ?

[Rog RJ]

Have you fitted the decoder in a socket? If so, is the decoder the right way round? Have you switched the lights on? Usually F0 on basic decoders.

Are you using the correct address?

Edit. Are the LEDs the right way round?

[Smudge617]

The decoders are function only so its hard wired, both decoders I tried are brand new, so they are at the default address, and I can read all the CV's on the decoders when on my programming track, also I used a circuit tester and a Hornby DC controller (with correct resistor) and the LEDs work both before adding a decoder as well as after removing them, which is why I'm baffled as to the problem. I've retro fitted lights to 7 loco's, both Diesel and steam, first time I've had an issue doing this, apart from the Eurostar power car which was mainly due to my lack of fine motor skills and old age, hence HELP ! please.

[Rog RJ]

Could you upload a picture or 2 ?

[Smudge617]

As you can see, I've wired the pick ups the wrong way round, hence in picture 2 the connection wires don't match up. The resistors are 1.5K 0.25W. When tested on track wiring in only two LEDs still had no luck.

[Chrissaf]

You seem to have the LEDs wired between the blue wire and the yellow wire. The blue wire is permanently positive. The yellow wire only goes switched negative when the decoder is told to go in reverse. The second image seems to show that the white decoder wire is left unterminated and doesn't have any LEDs attached to it.

Now assuming that the motor located decoder is given the same DCC address as the function decoder in the dummy motor car, then when you tell the motor controlling decoder at the front of the train to go forward, then the dummy motor car decoder will also receive the DCC 'go forward' command too. It then strikes me that it is when the train is going forward, that you want the LEDs in the dummy car [currently wired to the yellow wire] to also light up. In which case they would need to be wired between the blue and white wires and not between the blue and yellow wires.

Of course, if you do indeed only want the dummy car LEDs to light up when the train is going backwards, then the yellow wire is the correct wire to use.

My posted reply text above gives the two options as it is not clear from the content of your posts raised so far as to what your intentions are with regard to directional lighting. Normally, you would have both white and red LEDs at each end that change colour with direction, but your images seem to show only white LEDs and the white wire unterminated, which is unusual for a 'directional lighting' implementation.

You have also previously stated that the LED wiring polarity is correct. But I see that you are using red and black wires on the LEDs. If red is positive and black is negative [normal colour convention for voltage polarities]. Then the red LED wires should go to the blue decoder wire and not the yellow or white. Your wiring in the photos would only be correct if the red wire is the negative side of the LED and the positive side of the LED are the black wires. LEDs will not light up if reversed.

[Smudge617]

As usual Chrissaf you are correct and I am an idiot, the white wire is not attached yet as I do each part of the wiring in separately ie. wire headlights - test, wire tailight- test. The lights are to work protypical. As I have only got as far as doing one set of lights before hitting this problem, and idiot me totally forgot that blue is Positive NOT Negative as I have it wired at present, so switch Blue and Yellow (I always wire Red Positive, Black Negative) and I should be good to go, what a rookie mistake to make. Thanks Chrissaf, you saved my bacon, again. And also thanks for the advice on the wiper pickups, as you can see, work a treat