They're both right. Upgrade the alternator and tighten or replace ( your probably gonna have to anyway if you change alts) your belt. There are kits available from several vendors, TrailTough, Low Range and even ebay has a kit with mounts and such. Good upgrade if your running anything more than stock equipment, even an amp and head unit will draw too much for the wimpy stock alternator. Check your battery too, make sure it's up to snuff.