© 2017 AAMP Global. All rights reserved. PAC is a Power Brand of AAMP Global.PAC-audio.comPacific Accessory CorporationPage 1Rev. 0 7 0 617Advanced Amplifier Interfacefor FordAP4-FD21The AP4-FD21 provides a 6-channel pre-amp output for use with aftermarket audio equipment. Using the full range,fixed level head unit output, in conjunction with CAN messages, the AP4-FD21 delivers a variable 5v RMS pre-ampoutput with fading, balance, equalization, and level control capabilities. The module also retains all audio from othervehicle features such as factory navigation prompts, Bluetooth, SYNC, and parking sensor chimes. A data controlledremote amplifier turn on wire is also provided by the AP4-FD21. When used in conjunction with the APA-TOS1 (soldseparately), the module can provide a variable 2-channel fiber optic digital audio output (TOSLINK).Introduction and FeaturesImportant Notes1. This interface is only compatible in vehicles equipped with a data bus controlled premium sound system. To verifycompatibility, look for a Sony badge on the door speakers, center speaker, or factory sub woofer.2. The factory amplifier must remain connected, and in the vehicle after the AmpPRO has been installed.3. The remote output is rated at 2A of current. If more current is needed an external relay must be used.4. The remote output may remain active once the key has been removed if the vehicle needs to pass chime or SYNC audio.5. If your chimes played through the factory speakers, and all speakers have been disconnected from the factory amp, allchimes will then play through the speaker in the dash.6. Channels 5 and 6 are non-fading outputs. The output level of channels 5 and 6 can be controlled using the supplied levelcontrol knob.7. The chime volume and minimum volume levels are set to 0 dB by default. If you are happy with this level in your particularapplication then additional adjustment is not required. Please refer to the Setup and Configuration section on page 2 formore details.8. Ford Focus: You cannot use the steering wheel controls to activate the chime and minimum volume adjustment.9. The level control knob must be connected in order to manually adjust the chime volume and minimum volume settings.10. The factory radio's speed controlled volume and surround sound mode are not supported by the AP4 outputs.11. No adjustments can be made manually using the programming button, or the factory SWC when the module is connected toa PC.Wiring Connection ChartTo AftermarketAmplifierNon-FadingRearFront1(L) 2(R) 4(R) 5(L) 6(R)3(L)Remote Turn On Output2A Max OutputTo VehicleHarnessTo RadioTo LCDScreenNon-FadingLevel ControlKnobTo VehicleHarnessAP4-FD21-HAR