Toyota Repair: 1989 Toyota truck wont start, dead batteries, negative cable

Question
Hey. The truck (350,000 miles v6 4wd)started fine yesterday, today nothing but fast clicking sounds seemingly coming from the passenger side of the engine compartment.  Dash lights, door buzzer, dome lights,headlights, brake lights all getting dimmer; backup lights won't engage; battery bought 5/08; distributor cap, wires & plugs replaced 9/08; rebuilt starter installed 11/06.  I've had plenty of dead batteries, but have never heard the fast clicking noise before. Any ideas off the top of your head, or from deep within for that matter?!  Thanks, cj

Answer
Check the battery connections, make sure they are tight and there is no corrosion, the rapid clicking is caused by low supply voltage so the battery could still be the problem, try to jump start with another good battery, after it's running disconnect the negative cable, the engine should keep running, if it dies the alternator is not charging the battery.