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Decoder Error? headlight wont turn off.

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  • Member since
    January 2004
  • From: marion
  • 234 posts
Decoder Error? headlight wont turn off.
Posted by alcodave on Monday, November 29, 2010 2:36 PM

Hi guys, I have a few questions about my TCS M1P-SH series Decoder. I did the install on an Atlas HO Genset locomotive. The engine functioned properly in DC mode and all lights worked. I wasn't sure  which way the 8 pin decoder was supposed to face so I just put it in. The first attempt the Engine ran fine and in the proper forward and reverse according to the throttle, but the headlights would not come on. So I flipped the decoder around and the directions reversed and headlights came on. I solved the direction problem by changing the direction in the CV's. The problem is the light on one end wont turn off. I even reset the decoder and the light still wont turn off in the decoders factory settings, The other end of the locomotive lights functions fine turning off and on with the direction switch. I removed the decoder to double check and it does work perfect in DC.

 

I did the same exact install in another Genset with the same brand of decoder, I had the same thing with the lights and direction of decoder but it worked perfect after used the CV to change direction and the lights work fine. Any ideas on on why the first units light wont turn off? possible decoder error?

  • Member since
    February 2002
  • From: Mpls/St.Paul
  • 13,892 posts
Posted by wjstix on Monday, November 29, 2010 3:38 PM

Most decoders come set from the factory to do reverse lighting - i.e., the headlight is on only in the direction of travel. It could be a CV somehow is set so that the one headlight is always on. I would look at the TCS instructions, it will show you how to set the CV's so the lights do what you want.

p.s. real locomotives don't use reversing headlights, it's just a model thing, so many people set the CV's so they are on all the time. I like to set them so the headlight is on bright in the direction of travel, but the other headlight is dim. It's easy to do with TCS decoders.

Stix
  • Member since
    February 2002
  • From: Reading, PA
  • 30,002 posts
Posted by rrinker on Monday, November 29, 2010 10:10 PM

 The normal wiring of the NMRA 8 pin plug is such that nothign should be damaged by plugging the decoder in backwards - however it seems that you may hve blown one of the function outputs, if the light stays on and you can;t turn it off with F0 or reversing direction. After a reset the lights should be basic directional lights, so the one shoudl go out when you change direction. Always on is one failure mode. TCS will replace it, they have a 'goof proof' warranty where the first replacement is on them, even if it was something you did wrong wiring it up.

         --Randy

 


Modeling the Reading Railroad in the 1950's

 

Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.

  • Member since
    January 2004
  • From: marion
  • 234 posts
Posted by alcodave on Monday, November 29, 2010 11:36 PM

Thanks for the info. I emailed them too and will make contact about trading the decoder in.

  • Member since
    February 2002
  • From: Mpls/St.Paul
  • 13,892 posts
Posted by wjstix on Tuesday, November 30, 2010 9:01 AM

In re-reading this, it seems odd that the engine originally responded correctly to the forward command, but no lights went on. Normally, if you put an 8-pin decoder in backwards, it would go backward when you wanted it to go forwards, and the lights wouldn't work. What type of engine is it?? Are you sure which end is the "front"?? Some manufacturers will make say the short hood the "front" of their models even though a particular railroad that the model is decorated for considered the long end the "front"...or vice versa. For example, IIRC Atlas considers the long nose of their RS-3 to be the front, even when the model is decorated for a railroad that considered the short nose the front. So if you correctly installed a decoder and selected "forward" it would go towards the long hood's direction...which is really backwards.

Anyway, it's possible too that your decoder is working fine, but you may have affected some type of diode in the Atlas lightboard that is causing the light to be on all the time instead of work directionally.

I would try playing with the CVs, perhaps try to see if you can get the headlight that's on all the time to dim when the engine is going the other direction, or dim when the engine stops. As I noted earlier, real engines don't use directional lighting so if that's the only problem it may be OK to just leave it as is??

Stix
  • Member since
    January 2004
  • From: marion
  • 234 posts
Posted by alcodave on Tuesday, November 30, 2010 2:55 PM

It is the Atlas Trainman Plus Genset Switcher Locomotive. The forward end was the Short hood end in DC and it reversed when I added the Decoder. The F is also painted on the SH end.

  • Member since
    February 2002
  • From: Mpls/St.Paul
  • 13,892 posts
Posted by wjstix on Tuesday, November 30, 2010 5:03 PM

alcodave

 The F is also painted on the SH end.

OK, but on an Atlas New York Central GP-7, the F would be on the long hood, but the chassis is still set up for the short hood to be the front...or the short hood of an Atlas NP RS-3 would have the F on the short hood, but the chassis is still set up for the front to be the long hood. They don't change the wiring based on which end the prototype railroad considered the front. Wink

Stix

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