I知 trying to install an amp and sub to the factory system on a 2004 530i. It has the standard sound system, with a very small subwoofer amp. I知 planning on tapping in to those sub frequencies coming out of the stock subwoofer amp, using a line out converter (speaker level to RCA converter) to a JL 2501 amp which will drive a JL 12w3 sub. I need some opinions on what is what on this stock wiring harness coming out of the small subwoofer amp on the standard U.S. audio system. This is the small silver box on the left side of the trunk. I知 pretty sure I know which ones are the speaker wires, I just don稚 know what the positive and negative wires for each one are, or how to test the polarity. I知 open to suggestions.
Don't I really just need the sub frequencies the amp is putting out, so as long as I tap into the pair on **one** of the subs, does it matter which way I feed the LOC concerning polarity? Can't I just hook up one of the RCA's to the amp as input?
Factory wiring harness:
Going from left to right. SMALL BLACK WIRES-input signal from head unit (MASK computer). FIRST SUBWOOFER PAIR-brown/white stripe, red/blue stripe. SECOND SUBWOOFER PAIR-brown/yellow stripe, red/white stripe. AMP REMOTE TURN-ON-small white wire. POWER-thick red wire. GROUND-thick brown wire.