1994 Toyota 4Runner Electrical Problem

I got a 1994 4runner with a 3.0l v-6 with about 81,000 on the engine. All of the sudden I got not power to start the engine. I get the click click click. If I work it I can get just enough power to start it. Once it starts it runs good, but when the power items are on (A/C, Radio, Turn signals) the power fluctuates. At low idle the lights dim. Right after I stop and for abour an hour it will start right up, too much longer and it is dead. Is this an alternator or a battery problem?