A loco can move slightly on the program track, but power is too low to run it. This is normal. It sounds like you have lost track of the loco address (or it has lost track of you). Get a readout on CV1 (the 2 digit loco address), CV17 and 18 (the 4 digit address) and CV29 (the mother of all CVs). From CV29 you can determine whether the loco is configured to use 2 digit (CV29<32) or 4 digit addressing (CV29>=32), and from CV1 or CV17/18 you can determine what address you actually have. (Note that to determine the 4 digit address that has been programmed, you need to subtract 192 from the value in CV17, multiply the result by 256, then add the value in CV18. Thus CV17/18 values of 227/23 work out to be loco address 8983) Option 2 is to reset the decoder to default values and try running on 2 digit address 03 before starting over.
Doug, That was indeed my problem. I've got the loco running again, but still no light. I switched the wires as Bob suggested to no avail. The light doesn't even flash now, it does absolutely nothing. Thanks for your help.
I would suggest re-reversing the light connections then. An LED wired backwards will not light at all.
