Trains.com

Subscriber & Member Login

Login, or register today to interact in our online community, comment on articles, receive our newsletter, manage your account online and more!

Athearn SD70ACe Ditch lights and 8-pin DCC decoder

4967 views
4 replies
1 rating 2 rating 3 rating 4 rating 5 rating
  • Member since
    February 2010
  • From: Hillsboro, Oregon
  • 934 posts
Posted by Eric97123 on Sunday, December 19, 2010 1:03 AM

I just picked up one today and the right light appears burned out.. Is it an easy replacement?  

  • Member since
    February 2006
  • From: Germany
  • 524 posts
Posted by faraway on Friday, December 17, 2010 6:32 AM

Randy, you are right. They are wired parallel and the light has to go through light pipes.

I did rewire both bulbs with 1.2kOhm resistors to PA1/2 cables at the DCC decoder. They are working fine but somewhat darker than the head light.

Thanks for leading me into the right direction.

Reinhard

  • Member since
    February 2002
  • From: Reading, PA
  • 30,002 posts
Posted by rrinker on Thursday, December 16, 2010 8:43 AM

 I'm pretty sure that ont he Athaern board they are conected both to what ends up being the same function wire. I think there are additional pads ont he Genesis boards to move one of the lights to it ends up connected to F2, but I've never worked on one as I don;t model modern era. Also I do not think the bulbs themselves are right in the ditch light castings liek the headlights are, there are light pipes involved, so they will be dimmer no matter what. To get everything alike you will probably need to look to using surface-mount LEDs for all lights installed directly in the castings, both ditch lights and headlights.

                                        --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
    February 2006
  • From: Germany
  • 524 posts
Posted by faraway on Thursday, December 16, 2010 2:27 AM

May I bring this thread back to live.

The wiring of the ditch lights was no problem and they are operational but there is "something" wrong.

They do shine not as bright as the front and back lights. They look like dimmed and the activation of one of them will glow both. I did check my simple wiring (PA1 and PA2 to the left and right most wire of the 9-pin connector) 100 times. The programming is also ok but I can not activate only one of the ditch lights.

Did Athearn do "something" special on the board? How do they manage to get the 1.5 volt out of the decoder FA1 and FA2 exits? I guess there is something more than a simple resistor involved.

This might be no specific SD70ACe question but might be valid for all similar Athearn light boards.

Thank you for any insight and help

Reinhard

  • Member since
    February 2006
  • From: Germany
  • 524 posts
Athearn SD70ACe Ditch lights and 8-pin DCC decoder
Posted by faraway on Wednesday, December 15, 2010 11:05 AM

I run my brand new Athearn Genesis SD70ACE with a 8-pin DCC decoder (Zimo MX630). It looks like the ditch lights are not connected to the 8-pin socket.

My guess/assumption is that the ditch lights are separate wired to FA1 and FA2 on the 9-pin connector. I assume that because I found some programming instructions of US 9-pin decoders but nothing is mentioned about wiring.

I do further understand the two outermost wires of the 9-pin connector (and on the PCB) are the FA1 and FA2 wires (green and purple) to be used.

Question: are both assumptions correct?

In that case I could simply solder the corresponding FA1 and FA2 wires of the 8-pin decoder (that has all 9 wires) to the PCB wires of the 9-pin plug. The other 7 wires will go unchanged through the 8-pin plug.

 

Some time later:

I did discover the pin layout at the NMRA site and could proof my assumptions. No reply required the ditch lights are "on"Smile

Reinhard

Subscriber & Member Login

Login, or register today to interact in our online community, comment on articles, receive our newsletter, manage your account online and more!

Users Online

There are no community member online

Search the Community

ADVERTISEMENT
ADVERTISEMENT
ADVERTISEMENT
Model Railroader Newsletter See all
Sign up for our FREE e-newsletter and get model railroad news in your inbox!