Been a while since I posted, forgot my SN and had to create a new one

Im having problems with my idle on my 90 Integra. The battery light just appeared, and all of a sudden my idle is surging. (Its jumping up and down from 1k to 2k repeatedly) I can see the headlights get dim, and then becomes bright again.

Anyone know what the exact cause of this is? Is it a dying battery? alternator?

Please help! Thanks

 

vaccum leak probably.

 

i would say alternator

 

surging idle is usually a vacuum leak