New DCC Thunder Chief, Function 10 (lights on/off) isn't working

[steve1972]

I am new to model railroads and just bought a Thunder Chief DCC diesel locomotive set for my son.  Nearly everything seems to be working, however the Function 10 (turning the lights on/off) I have only gotten to work once. 

Some of the other functions were a bit intermittent, but in the last day all of them have been working reliably with the exception of turning the lights on/off.  They are always off.
Function 8 (mute) has always worked.  The sound functions (1, 2, and 3) initially were a little unreliable, but now seem to work all of the time.  The function 10 only worked during one session (during that session it worked reliably). 

I've checked all of the track connections and everything looks good, re-plugged everything.  Gone through several unplug/power cycles etc.  I haven't re-programmed anything (everything is at factory default).

Wondering what could be the issue? Bachmann support has suggested that I see if the light has gotten twisted around (I'll have to look at that tonight). Any comments/help much appreciated.

[Hunt]

While you have the shell off check for loose wires and poor connections.

If the locomotive has the wires connected to the printed circuit board with caps instead of solder, reseat the caps making sure the bare part of wire is in good contact with the PCB pad.

[Doneldon]

steve-

If everything works except the lights the odds are that the decoder is just fine but either the light is burned out or there is a wiring problem. It is unlikely that the light on a new loco is burned out so I'd start by inspecting the wiring from the decoder to the light. It sounds to me like you had a bad connection which is now just a complete fail. If you don't locate a bad connection, rig up a light you can test at every connection. The first one which doesn't light the light will show you that the previous connection was bad or the wire is broken between the previous connection and where you are. Rig up a jumper between the two points. It should light, confirming that the problem is a broken wire. Of these possibilities, a bad connection is a lot more likely that a broken wire. Good luck, and tell us what you discover.
                                                  -- D

[steve1972]

Many thanks for the debugging suggestions.  My work schedule has prevented me from giving it a try, but hope to get some time in the next day or two.  Will let you know how it turns out.  Thanks again!

[steve1972]

Good news!  I removed the shell to check things out.  Couldn't see anything wrong, but simply re-positioned the lead wires and now the light is working well.  If it stops working again I at least know where the problem lies, but hopefully we're all set now.

Thanks again for the help!
Steve