Spectrum 4-6-2

[38engines]

My 4-6-2 steam engine won't run, but the headlight still lights up. What should I be looking at?

[SteamGene]

Get your ear close to the loco under power and listen for the motor hum.  If it doesn't hum, either the motor is shot or there is a wire loose to it.  If it hums, then there is something wrong with the gear tower.  How old is it?  Are you the original owner? 
Gene

[38engines]

There is no humming. The engine is only 3 years old, and I am the original owner.

[hobo1]

make sure the wheels on the tender are installed correctly or it will create a short and the loco wont run

[SteamGene]

If there is a short, the light won't light.  Your problem is either a blown motor (rare, AFAIK) or a bad electrical connection.  Since you are the original owner, your best course of action would be to send it back to Bachmann, unless you have the skills to find and fix the break yourself.
Gene

[Yampa Bob]

Remove the shell, if you have access apply DC power directly to the motor brush terminals. If the motor runs, you have a wire loose or broken, if it doesn't motor is bad.