2001 ford windstar stereo works but no sound from speakers

I have a 2001 ford windstar se, after a failed attempt at installing an amp & sub, my car speakers don't work, my pioneer stereo comes on and seems to be fine but no sound. please help ! no clue !
i have unhooked all cables from amp to stereo It's really tough to say without looking at it, but if you are sure you have it wired like it was before, then the "fail attempt" part has me worried
Dude i have the same problem with my 1994 nissan altima new head unit/new spkrs and no sound. And yes it's driving me insane. There is nobody here named "dude" and you need to start a new question of your own, not hijack this one.