Weak signal to amp

Hi, all. I have an 01 gt w/mach 460 system. I have hooked up my system like the one described in mustang world but I think the signal is too weak. The subs do not pound at all. I have a blaupunkt 2150 amp which puts out 400 watts rms @4ohms to the subs. The subs are 2 10-inch infinity perfects wired to 4-ohms. The amp comes with something like a line out converter as it doesn't have high level inputs. Also, the amp should turn on whenever it receives a signal but it doesn't so I had to run a remote wire. Is there a different wire that i can tap. Also tried tapping the above the rear deck and I only gave me highs. Where would the wires to the subs be from the amps? Does anyone have a wiring diagram for the rear amp/speaker configuration. Thanks in advance.

I found out that the line out converter on the blaupunkt amps do not work very well. I went to Best Buy and bought a new one. They work great. I also found out that the "data cable" trick is not really a data cable. It's just the speaker wires that connect the amp to the 5x7 subs so its a regular speaker line. I found out when I aquired a wiring diagram for the system from Ford.

There is no power anntena wire for my mustang which is an 01 gt. I just tapped fuse #32 under the dash. It is a 15amp fuse and you just stick the remote wire into either side of the pins. This just turned on my amp whenever my car is on.