QuestionQUESTION: I have a 2003 cadillac cts and i want to remove the factory amp. I have a schematic for the amp connectors and i notice that on of the pins is labeled class 2 serial data. My question is what do i do with this wire. I'm installing a aftermarket amp. Oh i have the bose audio system. And i am going to run new wires for the aftermarket amps.
ANSWER: Hi D,
Unfortunately, if you're planning to keep the factory head unit in the vehicle, then removing the factory amp isn't going to be practical; and the serial data system is the reason why.
The serial data wire carries a digital communication signal between the head unit and the Bose amplifier. This signal tells the amplifier when to turn on and off, as well as controlling the system volume, balance and fader settings. The audio wires from the head unit to the amp just carry a fixed, low-level left and right audio signal. The output level on these wires doesn't vary as you adjust the volume control on the head unit; instead, the digital signal on the data bus wire instructs the amplifier to increase the output level.
That's why you're not going to be able to disconnect the factory amp and just install an after-market amp in its place: the after-market amplifier won't recognize the data bus signal. You can probably adapt the head unit's output wires to feed an audio signal into your new amplifier's inputs, but you won't be able to adjust the volume, balance or fade controls through the factory head unit.
This doesn't mean you can't install an aftermarket amplifier/speaker system in your vehicle. You'll just have to use the Bose amplifier's outputs to feed the after-market amplifier's inputs, rather than getting the audio signal direct from the head unit. The way to do this is to use a summing device, which can take the separate front, rear and subwoofer outputs from the Bose amplifier and combine them into full-range outputs for your amplifier. The best summing devices include built-in digital signal processing to remove the effects of the Bose amp's built-in equalization curves.
Some devices that should perform well in your vehicle would be JL Audio's Cleansweep system, Rockford Fosgate's 3Sixty, or AudioControl's DCQ-8.
Hope this helps!
Brian
---------- FOLLOW-UP ----------
QUESTION: I'm sorry i wasn't very clear before on exactly what i was doing. Yes i am replacing the factory unit but i am trying to keep my dic screen. And the only wires i was unsure about was the class 2 serial data wire. I have two class 2 serial wires coming from the factory radio connector labeled C1 and i have one on the factory amp.
AnswerYou shouldn't have to do anything at all with the data bus wires; just make sure they can't short out or connect to anything with DC voltage. Mis-wired data bus lines can cause some really strange problems with other vehicle systems, but you shouldn't have an issue if you're just disconnecting them. I suspect that one of the data bus wires at the head unit is the same wire that's found at the amplifier, but I'm not certain of that.
Good luck with your project!
