Do i need to change my alternator?

so i have a 2002 honda civic and just wen i thought i was done replacing everything bam i get hit with some more bs. So i just bought a brand new battery in july but today one of my headlights wont fully turn on i thought maybe its just blown but them my kenwood radio that was installed is on demo and cant take it out of it so thats not a good sign so im just guessing its the alternator but please anything helps?

Read more: Do i need to change my alternator?