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NCE decoder lighting headlights wrong...

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NCE decoder lighting headlights wrong...
Posted by JasonA on Friday, January 12, 2018 8:57 AM

I've started my foray into DCC and I've run into a hitch I'm not sure how to resolve...

I installed a decoder in an N scale Atlas SD60m (NCE brand decoder, NCE Power Cab DCC system) and what happens is, when I run the loco, the wrong headlight comes on.

So when it's running "forward" the rear light is on, and in reverse, the front light.  When I initially tested the unit on DC power, it was running "backwards" to the direction switch on the power pack, but I figured I could fix that with the reverse bit.

Now that it's on DCC, with the reverse bit set to 0 (normal running) it runs correctly except for the headlights...

I know the decoder is installed correctly (there's only one way it will install and make contact with the motor contacts,) I stuck the little bit of insulating tape in the location specified in the directions, so I'm currently out of ideas.

I saw a posting here about playing with CV33 and 34, now I can keep the front light off, but the back still comes on...

 

Any suggestions?

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Posted by woodone on Friday, January 12, 2018 9:57 AM
sounds like you may have the motor leads hooked up in reverse. Try switching the orange and gray wires at the motor.
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Posted by tstage on Friday, January 12, 2018 10:02 AM

Jason,

Was your NCE decoder installation plug-in (e.g. NMRA socket) or hardwired?  If hardwired then I would flip the motor leads as woodone suggested.

Tom

http://www.newyorkcentralmodeling.com

Time...It marches on...without ever turning around to see if anyone is even keeping in step.

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Posted by JasonA on Friday, January 12, 2018 12:08 PM

There definately wasn't a socket to connect it to, but there were also no wires to solder in.

It's a "drop-in" decoder that replaced the existing light board in the locomotive, using the same to contacts from the motor itself.

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Posted by tstage on Friday, January 12, 2018 12:19 PM

Jason,

Swap the orange and gray motor wires and that will fix your issue.

Tom

http://www.newyorkcentralmodeling.com

Time...It marches on...without ever turning around to see if anyone is even keeping in step.

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Posted by JasonA on Friday, January 12, 2018 12:35 PM

Below is a picture of the frame and decoder, there are no motor wires.

That being said, and I appreciate the suggestions, I managed to get the lights working in a manner that I'm happy with by playing around CVs 33, 34, 120, and 121.  The rear light comes on in reverse, the headlight is on all the time.

So, honestly again, thank you folks for taking the time to help.

 

 Locomotive frame and decoder

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Posted by rrinker on Friday, January 12, 2018 1:07 PM

 Looking at the decoder instructions and comparing to your photo - I think you may have the decoder upside down. That's the same as swapping the motor wires left to right. Not front to back backwards - the motor tabs wouldn't be near the slots if that were the case, but upside down.

 Although which decoder did you put in? On the NCE web site, the one listed for the Atlas SD60m is the N12A1, but that oen shows as having regular through hole LEDs and your picture shows a decoder with surface mount LEDs.

                                          --Randy


Modeling the Reading Railroad in the 1950's

 

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

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Posted by JasonA on Friday, January 12, 2018 1:19 PM

Even more, although it's hard to see in the picture, the model on the decoder isn't the same as the model NCE specified on their website and that I ordered from my hobby shop and that shows on the instructions included!

But, I contacted NCE about it and they indicated it is the correct board for the locomotive, so I suspect the LEDs were a manufacturing choice to save some money.

 

As for the motor tabs, do you mean they would need to be flexed up over-top the board, instead of making contact underneath as I currently have it?

Which, from just taking a better read of the directions, seems to be the case...

To quote the great sage himself: d'oh!

Looks like it's time to re-disassemble the loco...

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Posted by BigDaddy on Friday, January 12, 2018 5:30 PM

JasonA
As for the motor tabs, do you mean they would need to be flexed up over-top the board, instead of making contact underneath

I don't see your board online, but the boards I see, don't have the NCE and model number visible, so it is upside down.  Uninstalling the board and flipping it over may be preferable to dealing with wires that are too short to go to the correct contact.

 

Henry

COB Potomac & Northern

By the Chesapeake Bay

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Posted by rrinker on Friday, January 12, 2018 6:33 PM

 No, you don;t have to do anything tricky with the motor tabs. Just take the decoder out and flip it top to bottom - the side that is facing up now should face down into the loco frame. That will effectively swap the motor leads without actually swapping anything.

                                      --Randy

 


Modeling the Reading Railroad in the 1950's

 

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

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  • From: Phoenix, AZ
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Posted by woodone on Friday, January 12, 2018 6:48 PM
Well I for one don't like the idea of the motor contacts just pushing up on the decoder. I solder a short wire from the motor contacts to the decoder. I have run into too many locos not running because of poor connections between motor and decoder.
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Posted by JasonA on Friday, January 12, 2018 9:28 PM

Final update on this, hopefully...

I tried flipping the decoder over, and it turns out NCE must've made some other changes, as it looks like to get the board in "cleanly" I'm going to need to file / Dremel / cut out a sliver of the top of the metal frame.  There's some circuitry that otherwise gets pressed into the top of the frame, which prevents the board from sitting flat and the chassis from lining up correctly.

 

So, that's tomorrows project, I've already got the motor etc out of the frame, I just need to take it down to my workbench and Dremel out the bit.

 

I might try using an older metal-working file I have, although it's rather large, it does have a more agressive tooth pattern than the hobby file I was trying to use.

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Posted by woodone on Saturday, January 13, 2018 7:56 AM
What is the decoders part number? All of information we have does not show what decoder you are working with.
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Posted by JasonA on Saturday, January 13, 2018 7:59 AM

It's a NCE N12A1.

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Posted by woodone on Saturday, January 13, 2018 8:11 AM
Then there is no way you can install the decoder upside down! There would be no pads for the motor contact strips to make contact with the decoder? You should have two square pads on the decoder board that face down and make contact with the two motor contacts. With the photo it is hard to see, but are there slots to fit the motor Contact strips into?
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Posted by JasonA on Saturday, January 13, 2018 8:20 AM

The pads are there, but reading (well, re-reading) the directions make it sound like the contact pads should face up, not down.  BUT on the side of the pads there's also a bunch of surface mount circuitry, which if I try to install it the "correct" way, get in the way.

Plus, it seems in the "correct" orientation, the motor contacts don't contact very well.

Flip it over, and the motor contacts press up against the pads and make decent contact, but then I'm back to my original problem.

There are no "slots" to feed the tabs through (despite what the directions seem to indicate.)

 

To be honest, I'm kind of thinking of just flipping the board back over the way I had it before and putting everything back together and just dealing with it.  Mostly because I worry I might cut a bit too much out with the Dremel to make it fit in and have new, harder to fix problems...

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Posted by BigDaddy on Saturday, January 13, 2018 8:36 AM

Having only installed HO DCC boards, I was a bit confused. We have wires not tabs. The pics on the TCS installation page show to metal tabs coming through the replacement decoder.  see last picture

https://www.tcsdcc.com/Customer_Content/Installation_Pictures/N_Scale/Atlas/SD60/N_Atlas_SD60_CN.html

You said it was N12A1 but your picture looks like N14A1

 
 

Henry

COB Potomac & Northern

By the Chesapeake Bay

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Posted by JasonA on Saturday, January 13, 2018 8:52 AM

BigDaddy
You said it was N12A1 but your picture looks like N14A1

You are correct, the board does have N14A1 on it.  I contacted NCE before installing it and confirmed that it is the correct board.  And yes, even the NCE directions talk about "slots" but if you look at the picture, well, there's no slots (and I'm *NOT* creating slots! Wink)

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Posted by woodone on Saturday, January 13, 2018 10:34 AM

I don’t see the N14A1 on NEC’s web page? Not sure what you may have .I would install the decoder the way you had it installed at first. BUT I would use short jumper wires from the motor to the decoder and swap the location’s. That should have you running with the lights Correct!

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Posted by rrinker on Saturday, January 13, 2018 12:02 PM

 Ever since NCE updated their website, it's become a horrible mess to find anything. But it does appear they have no information on an N14A1 anywhere to be found, even the search doesn;t find it.

 Since it oonly appears to fit one way, put it in that way and use CVs to fix the lights. It's not CV33 and 34 in this decoder, the instructions mention that they both operate the same and you need to adjust the effects for each output to change the directionality. That's CV120 and 121.

 After resetting everything, CV120 is probably 129, for LED, on when in forward, and CV121 is probably 130, for LED, on in reverse. Just swap those, make CV120 = 130 and CV121 = 129.

                                         --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
    October, 2009
  • 15 posts
Posted by JasonA on Saturday, January 13, 2018 4:49 PM

That's what I went ahead and did earlier today.  No sense in fighting with it and making things harder than they need to be...

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