Bought audiofire box for 2-10'' subs pushed by 1000w amp. Used 4g wire for 12v and ground (which is good). I spliced into the L/R input wires BEFORE the stock apline amp. Sounds great when engine is off, but soon as it is turned on subs make just a tapping noise and thats it. Also HDDsounds terrible as well. Ordered a pac oem2 from crutchfield and will install tonight. But I also tried wiring my 12v to the 12v going into the stock alpine headunit, this time the subs work when engine is running, but cut out every now and then (the green light dims) prolly due to lack of power. Any additional help would be great! Also is the pacoem2 going to clear up the problem when I turn on the engine?

 

what sort of amplifier are you using? are we talking 1000w rms or peak? If it's pushing 1k rms at the resistance that your wired to, I'd consider maybe upgrading to a 2awg or bigger. As far as your audio connections go, take your signal straight from the back of the factory deck. +12v should come from a switched accessory source, I always use the ignition harness. Be sure that you fuse the connection as well. Be sure that your ground has all paint scraped away and that the body of the terminal is touching bare metal.