Audio Systems: Car Speakers, factory radio, stereo shop

Question
This is a pretty basic question.  I just bought a car that is a couple of years old.  I didn't realize it when I bought it that the speakers in the rear were not working.  I've heard them kick on once or twice while driving, but only for a few seconds and then I lose them again.  I'm assuming it's some sort of wiring problem, but I don't know where to begin looking.  Does this sound like something I could probably fix on my own, or would I need someone to look at it?

Thanks :)

Answer
Rebecca,

 well it depends on how excited you are about getting in there and trying =).. i can give you a decent path to follow but since the unit is prolly a factory radio it makes it harder to fix the wiring if its a major problem since you would need a schematic diagram but lets not put the horse before the cart lol .. ok turn your stereo on and go to the speakers that dont work bang on the cover a little and see if the sound cuts in and out ? .. if it does its one of two things a short in the speaker or wiring but more than likly its in the speaker ..so if you have a speaker laying around even a home speaker will work pull the non working speaker out and unplug/cut the wires with enough room to wire any terminal/plugs back on then wire in your test speaker * factory wires will have a light color and a dark color wire light is the + and dark is usually the -* .. now if you get sound your in for a quick fix just buy a new set of speakers and slap back in .. now if you get the same problem of cutting out or poor sound i would recommend taking it to a stereo shop so they can get a better look at it and will have the tools to finish the job .. hope this helps you out if you need anything else let me know

thanks