Last night my battery light came on while driving. I figured it was the POS battery that i still had hooked up (in my trunk, it's been relocated). So i ran home & swaped it out & put my optima in. Battery light was still lit. I kno the alternator is brand new, only has bout 3 weeks of use now & i kno the cables are nice & snug. I'm sitting here at work right now, trying to figure out what else it might be if it's not my alternator. I'm wondering from all the vibrations of my solid mounts if the lil 10mm nut on the alternator has some loose & is causing this.. i guess i'll be finding a battery charger on my lunch break to charge my battery enough to get home