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I currently have a 4 channel amp powering my speakers in my car. I intend to purchase a 12" subwoofer as well as an amplifier to power it. For my current amp, I've run a 4 gauge wire to the trunk. I'll acquire a distribution block and run 4 gauge wire to it, as well as 8 gauge wiring from the block to each amp. My question is how do I figure out the fuse size to utilize. For the present amp, I already have a 60amp fuse, and I'm not sure what size fuse I'll need to replace it with. Do I run a 120 amp fuse or keep my 60 amp fuse because the new amp would most likely require a 60 amp fuse as well? I'm pretty sure I only need a single 60 amp fuse, but I want to double-check before I go out and buy anything. Thanks.
I currently have a 4 channel amp powering my speakers in my car. I intend to purchase a 12" subwoofer as well as an amplifier to power it. For my current amp, I've run a 4 gauge wire to the trunk. I'll acquire a distribution block and run 4 gauge wire to it, as well as 8 gauge wiring from the block to each amp. My question is how do I figure out the fuse size to utilize. For the present amp, I already have a 60amp fuse, and I'm not sure what size fuse I'll need to replace it with. Do I run a 120 amp fuse or keep my 60 amp fuse because the new amp would most likely require a 60 amp fuse as well? I'm pretty sure I only need a single 60 amp fuse, but I want to double-check before I go out and buy anything. Thanks.
You need to add up the fuses for both amps. Most newer amps have built in fuses. If this is your case and one amp has a 30 amp worth of fuses (ex. two 15s) and the other amp has 40 amp worth of fuses for a total of 70 amps, then it's possible your current 60 amp fuse would be fine. This is because typically, when playing music (even at high levels), you'll rarely exceed the recommended fuse rating of the amp. If both amps require 60 amps each for a total of 120 amps, then you'll need a new fuse and might as well go with a 120 amp single "primary" fuse at the battery.
Consult your amplifier's manual to see if they have suggestions for different amp loads. It seems like more than not the amps come with fuses to cover their maximum rating at the lowest impedance. So chances are you'll be fine just adding up the fuses used in both amps.
Thanks for adding that. A lot of the cheaper kits sold as “4 gauge” wire is more like 6 gauge and copper coated aluminum (CCA).
CCA wire has a higher resistance and generates more heat and less energy than copper. If you have CCA wire that’s more like a 6 gauge it might not be safe to run much more than the 60 amp fuse that came with the kit. Especially if the wire is around 15ft or more.
This was one the best site I've seen for determining wire gauge and fusing required. Still is if you don't mind adding an extension to your browser. http://www.bcae1.com/wire.htm
