This is called a hunting idle and is caused by either a vacuum leak, dirty throttle body, or gummed up idle air control valve. Read this article on how to diagnose and fix

http://ricksfreeautorepairadvice.com/idl...

your timing may need to be adjusted, and if the timing is off you could have a bent valve that isn't closing completely causing misfires

You hay have a vacuum leak.

Sounds like a bad alternator. Have your alternator checked out it can be responsible for all for all of these symptoms.

the idle keeps goin up and down kind like if you were to hit the rev limiter but it is doing it at stop lights at all rpms and the lights on the dash dim it is not consent it is speratic ford torus 1997 also it seams like sum thing is draning the battery over a weeks time