Sub amp problems. Possible ground location??

[Bologna]

Thanks man. At idle with heater and radio on low volume the voltage under the hood matches back at the amp. 13.8 volts or so. Just making sure it wasn't a bad alt battery or ground since sears napa and interstate suggested these cars use a agm battery and that if you used a lead acid you would have voltage drop

I would use agm, but the different type of batteries won't give you a voltage drop.

The reason people suggest agm is because if you have a lead acid battery in your trunk, you don't want it to fall over and ruin everything lol

I run/suggest XS Power Batteries - They have never been outperformed by anyone as far as I know