well if your clutch was siezed then your car would have a hard time running or would not run because the single belt that drives all the accessories are all connected. what you will have to do if you havent already done so is take the belt off first. spin the outer part (the side the belt touches) if that spins freely then ok, next spin the inside. see if that spins. if id doesnt most likely your compressor is dead. but if the outer side spins, and the inside spins (with some resistance of course) then its possible that its your clutch. or more likely your magnet which engauges the clutch. also check your ac fuse. if its blown then thats another sign that your magnet is shorting or somehow drawing too much current.