Although the car radio wirings might defer depending on the make of your car, it is relatively simple to connect the speaker wires from the head unit accordingly. You can even buy an adapter for the factory radio that will connect to your factory harness and then all the speaker wires are available without the harness being cut off. They come with a wiring diagram that is very easy to follow.
You need to connect the fused power wire from the battery, and the RCA's to the amp from the adapter, and a remote wire to the amp from your factory radio (the wiring diagram with the harness adapter will tell you which one it is). There is another harness adapter that plugs into the factory stereo and then gives you the wires you need for the car adapter and then plugs back into the factory speakers for mids and highs.
Also, there are aftermarket line level converters that plug in between your wiring harness and your factory radio. Of course, it depends on your vehicle. METRA electronics has a couple called quick harness. They have them for BMW, Chrysler/Dodge 1985-up, Ford 1985-up, GM 1988-up, Acura/Honda 1998-up, Isuzu 1995-up, Nissan 1996-up, VW 1980-up. I would check your local car audio shops to see their availability.
The antitheft should not be a problem, as you are only using the signal from the speakers and it should still have a wiring harness in the back. You will be using a fused power wire from the battery to your amp. Nothing should change the antitheft part of the system. There is a turn on from just about any factory and aftermarket unit. They are used for auto antennas and not just turn on for factory or aftermarket amps.
You need to connect the fused power wire from the battery, and the RCA's to the amp from the adapter, and a remote wire to the amp from your factory radio (the wiring diagram with the harness adapter will tell you which one it is). There is another harness adapter that plugs into the factory stereo and then gives you the wires you need for the car adapter and then plugs back into the factory speakers for mids and highs.
Also, there are aftermarket line level converters that plug in between your wiring harness and your factory radio. Of course, it depends on your vehicle. METRA electronics has a couple called quick harness. They have them for BMW, Chrysler/Dodge 1985-up, Ford 1985-up, GM 1988-up, Acura/Honda 1998-up, Isuzu 1995-up, Nissan 1996-up, VW 1980-up. I would check your local car audio shops to see their availability.
The antitheft should not be a problem, as you are only using the signal from the speakers and it should still have a wiring harness in the back. You will be using a fused power wire from the battery to your amp. Nothing should change the antitheft part of the system. There is a turn on from just about any factory and aftermarket unit. They are used for auto antennas and not just turn on for factory or aftermarket amps.
