Does anyone know if this is a normal feature or is my decoder screwed up? The decoder is a Digitrax SDN144K1E mobile sound decoder. When it receives track power, the front headlight is always on and bright, regardless of the direction of travel. The rear light does come on when reversing, though (that's good). Pressing F0 appears to have no affect on either light, but does appear to affect the loco's speed (like it switches between full and half speed). While trying to debug this, I changed the forward light CV to do things like blink, and although it didn't have any affect on the light, it made the loco (motor) move in bursts. If this is intended behavior with the decoder, I have no idea what changed to make it operate this way. Is there a way to get it to function with directional lights that toggle with F0, like my other loco (running a Tsunami)? I looked all over bother the decoder's manual, the command station's manual (a Zephyr Xtra, by the way), and the general Digitrax decoder manual, and I couldn't find anything helpful... granted that since I have no idea what is the cause of the problem, it makes finding a solution a bit more difficult, especially when I'm new to DCC, decoders, etc. I figured I should stop messing with random CVs before I make the situation any worse... bad enough I can't get JMRI to read/write to my decoder to make it easier to work with. Thanks for any help.
You have probably had a short or overload in the headlight. Common (but not always) the function will remain lit after a short. I have caused a couple of decoders to fail over the years. They wind up installed in B units that don't need lights. One of the hard lessons learned on decoder installs. Test with a meter before applying power. Sometimes even testing doesn't show the short. Wires and connections get pinched after installing the shell. Most decoders have a decent warranty. Wasn't always like that. Martin Myers
I have taken care to avoid shorts. The decoder doesn't make direct contact with the frame anywhere besides the two electrical contact points, and I was extra careful and put tape along the frame where the two motor brush clips may make contact, just in case. I was looking through the decoder manual and started wondering if perhaps some of the FX3 values got changed. I see that some settings involve the F0 button and directional light behavior, but I don't understand how those settings work to see if I could correct them, if that is what's wrong.
Verify by checking CV29 that you are not in 14 speed step mode (either in your decoder or your command station). This is often the cause of crossups between speed control and light functions.
