My 91 DA has been acting weird, the head lights dim when the engine is reved or just sitting idle, and the rpms go up and down on there own when idle.

the battery gets drained within about 3 days, its a brand new battery.
i took it to autozone and got it charged tonight and then drove it over to get the alternator tested and its just fine.

they said it might be a short or messed up wiring from the alternator or something.

how would i go about checking this?
dont really wanna pay to get it checked out at a shop, cos im broke as all hell right now.


sorry if the questions dumb, hella noob haha

 

haha finally got it looked at today.
and the thing causing the problem was the fan!
it stays on too long and would drain the battery.
such a weird problem, i would of never thought of that.
at least shes back to life again<3 hahah