Ok, so I have been trying to install a 12" sub running off of a 400w amp by splicing into the rear inputs (pre-Bose). I have the power, ground and remote all run correctly. I am using 8 gauge wire with a 50A inline fuse.

I spliced into the pre-bose rear inputs and am running those into an LOC, which is running RCAs into the amp. The problem that I am having, is that every time I turn on the ignition, I blow the 50A fuse. I unhooked the RCA inputs and out to speaker wires thinking maybe there was something shorting it out there, but no, the fuse still blows. My next trial was to unhook the power from the amp and turn on the ignition. The fuse did not blow, so there is no short in the powerline itself, but when I touch the power to the terminal on the amp, I get power for maybe three seconds, and then the fuse blows. I turned down the gain on the amp, thinking I was running the amp too hard, but nothing changed.

Do you think I am running to small of a fuse? Do you think something is wrong with my amp? I have two 30A fuses directly in the amp, but they never blow, only the inline 50. I really am lost, any help is greatly appreciated. Thanks in advance

 

If you disconnected your speaker outs, My bet is your amp is bad. Although I'm surprised the in-amp fuses do not blow. Check you ground wires. Did you try changing out your amp fuses with fresh ones?

 

A 50 amp fuse can sustain up to 100 amp temporary draw. So for some reason your AMP is really pulling juice that it should not be. Sure sounds like the amp is bad or not wired correctly. Could just your positive and negative terminals at the AMP be in electrical contact. That would explain why the fuses for the amps never blow - cause they never receive current. With the power disconnected check the resistance between your + and - terminals at your AMP - it should not read zero.