Questioni read about your harness by pass but is there any other method of bypassing bucause it seems that all u need is to power the factory BA amp.
AnswerHi Alex,
Just to clarify, "bypassing" a factory amp means wiring it out of the system, and connecting speakers directly to an after-market head unit or amplifier. When you're installing a new head unit and trying to keep the stock amplifier working, that's called "integrating" the amp. It sounds like you're asking about integrating the amplifier.
Unfortunately, Chrysler sound systems have changed quite a bit over the past few years. It's not easy to power up the Boston Acoustics amplifier using after-market head unit; and even if you could, there are other obstacles keeping the after-market and OEM components from working well together.
Until recently, you could activate a Chrysler amplifier just by sending 12 volts to the correct wire in the radio harness. However, the newest versions of the Infinity and Boston Acoustics systems don't turn the amp on with voltage; they send a digital signal through the vehicle's data bus system. After-market head units can't duplicate this.
Now, there is a way to install an after-market deck and turn on the factory amplifier: you could just relocate the factory radio to another spot in the vehicle, and extend its power, ground and data wires so that it's still part of the system. As long as the factory radio is switched on, the amplifier will be switched on; and its' audio inputs can be connected to the after-market head unit. That would probably work, except for another new wrinkle.
With the older Chrysler systems, and virtually every after-market system, the volume and fader are controlled inside the head unit. The deck has four channels of outputs, and the output level varies according to the volume level and balance/fader settings.
Newer Chrysler systems don't work this way. They only have two channels of outputs--left and right--and no separate front and rear outputs. Also, the output level is fixed: it remains the same no matter what setting is selected at the volume or fader controls. The volume adjustment is done inside the amplifier itself, in response to digital control signals generated by the factory radio and sent through the vehicle data bus. Again, an after-market head unit doesn't have the ability to control the factory amplifier through the data bus system; so even if you've succeeded in turning the amplifier on, you can't control the sound through the after-market deck.
That's the reason for the after-market adapter modules. With a module like Metra's CHTO-013, you'd connect the RCA outputs from the new head unit to the adapter, which converts them for use with the factory amplifier's input system. It can communicate with the amplifier through the data bus, and sends the appropriate turn-on, volume and fader commands. Right now, an adapter interface is the only way to integrate a Chrysler factory amplifier with an after-market head unit.
Of course, you still have the option of bypassing the amplifier, and connecting the speakers directly to the head unit. However, this is really only practical if you're planning to replace the speakers with after-market upgrades. The stock speaker system doesn't match well with the typical 4-channel, full-range outputs of an after-market head unit.
Hope this helps!
Brian
