89 lx 4 banger alternator help

ok, i just bought this car yesterday... only $700 (89 lx 4 cyl manual w/ 195k on it... but new clutch)... and it made it home but died on the way to pick up my old car with a friend. we've narrowed it down to a lack of power (electrical)... and it'll start, but only when jumped (or the bats been charged by a charger). it'll only stay alive if you have the radio, lights, and wipers off and when it idles for a while i might have to rev it a lil to keep the voltage meter from dropping (thats when it dies, but when its not idling it seems pretty good). so it seems like the alternator is shot, or it could be the battery... or both. so i'm replacing both friday, but that alternator looks in a tight and nasty place to get at. someone said i may have to drop the engine to get to it... will i or can i just get at it from the bottom or wheel well? and how do i loosten the serpentine on this car... is it a tensioner? thanks for any help, and even though my new baby won't stay runnin for all that long, i'm now a proud probe owner. thanks everyone