I just put a decoder in my GP-38 that I took from another GP-38. It works fine, but when I turn the headlights on, the front comes on when I'm going backwards, and back comes on when going forward. How do I fix this problem? Any information at all is strongly neeed!
Thanks, Liam.
The white wire is for the front headlight and the yellow wire is for the rear headlight. If not wired this way, I suggest that you change it. If they are wired correctly, they can be reprogrammed to operate the way that you want. To do that, you will need the complete manual for the decoder. That is usually available for download at the decoders manufacturers web site. If you have Decoder Pro set up on your computer and connected to your DCC command station, you can change them using it.
If the lights ARE wired correctly, the motor leads could be wired in reverse. You could change those. Then if the locomotive runs in reverse when forward is selected, you will need to reprogram CV 29 to reverse the direction. If you have an NCE system it will be really easy. If not, you will need to do the binary calculation. I'm sure there is a web site somewhere that will tell you how to do that. Since I have NCE and use Decoder Pro, I don't remember how to do it. Perhaps someone else can.
Elmer.
The above is my opinion, from an active and experienced Model Railroader in N scale and HO since 1961.
(Modeling Freelance, Eastern US, HO scale, in 1962, with NCE DCC for locomotive control and a stand alone LocoNet for block detection and signals.) http://waynes-trains.com/ at home, and N scale at the Club.
The simplest cure is to unplug the decoder and turn the plug around, and then change CV29 to reverse the motor direction. Or the decoder may already be set to reverse direction, and you need to change it back to normal direction with CV29 after turning the plug around.
Try function remaping by setting CV 33 to 2 and CV 34 to 1
gandydancer19 If the lights ARE wired correctly, the motor leads could be wired in reverse. You could change those. Then if the locomotive runs in reverse when forward is selected, you will need to reprogram CV 29 to reverse the direction. If you have an NCE system it will be really easy. If not, you will need to do the binary calculation.
If the lights ARE wired correctly, the motor leads could be wired in reverse. You could change those. Then if the locomotive runs in reverse when forward is selected, you will need to reprogram CV 29 to reverse the direction. If you have an NCE system it will be really easy. If not, you will need to do the binary calculation.
I have a Digitrax Zephyr Extra system, and you don't have to do a binary calculation: just deduct 1 from CV29 to reverse motor direction. If that doesn't solve the problem, the OP should check the settings for CVs 49 & 50 (forward and reverse lighting) and then CVs 33 & 34 as suggested above.
Dante
Other way around. Actually, it depends on what CV29 is currently. If it's an even number, add 1. If it's an odd number, subtract 1. If CV29 is an even number, then it is the 'normal' forward direction, to reverse it, add 1. If it is already an odd number, then is is already set to run reverse, so subtract 1 to get to the next lowest even number for normal forward operation. Pretty ingenious - all the other options in CV29 result in even numbers no matter which combo you select (long address, short address, speed table, no speed tables, DC operation, no DC operation). Only the direction setting changes it to an odd number. No binary calculations needed.
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
Randy,
You're correct-I should have given your explanation. I had to do that (add 1) on one of my locos. I should triple check my late-night posts!