I am installing a sub in my 05 G35 Coupe. I want to know if I can connect the amp to the fused (125 Amp) battery terminal, or if I should connect it to the un-fused terminal. I am using a 550 watt (50 amp) Class D amp with 4 AWG wire and a 50A fuse off the battery. I want as much protection as possible which is why I am considering using the fused battery terminal, I am just not sure if I am going to overload the 125A fuse given the other items connected to it.

 

Don't tap a sub off of other systems in the car, it needs to attach directly to the battery with it's OWN fuse.