PAC AmpPRO AP4-FD21 Amplifier Integration Interface for Select Ford Sony & B&O Vehicles

The PAC AmpPRO AP4-FD21 amplifier integration interface lets you add aftermarket amplification to the exact factory-audio applications listed below without replacing the original radio. It provides clean amplifier-ready outputs while retaining supported factory radio controls, warning chimes, navigation prompts, Bluetooth audio, and other application-dependent audio functions.

At a Glance

• Vehicle-specific AmpPRO interface for upgrading the factory amplified audio system while keeping the original radio
• Front, rear, and subwoofer preamp outputs rated up to 5 volts RMS
• Retains supported factory volume, fade, balance, tone controls, chimes, prompts, and communication audio
• Includes a wired subwoofer-level control for convenient level adjustment
• Optional TOSLINK output is available with the separately sold PAC APA-TOS1.
• Aftermarket amplifier, amplifier power wiring, signal cables, speakers, and application accessories are sold separately

Exact Vehicle Compatibility

Find your vehicle below and match the year, model, factory audio system, screen, connector, and equipment details in the same row. Applications are derived from PAC’s June 2026 interface matrix and validated against the current dealer product record. If the details do not match, contact MCOR before ordering.

Compatibility & Installation Requirements

• Factory system: compatible data-bus-controlled factory Sony or specifically listed B&O amplified system.
• Factory amplifier: The factory radio and factory amplifier remain connected for the supported upgrade path.
• Amplifier connections: Use the application-specific PAC speaker harness and load resistors listed in the table when required.
• Programming: Install the current PAC firmware and follow the current application guide before final system configuration.
• Requires a compatible data-bus-controlled amplified system.
• 2018-2019 Super Duty may use Sony or B&O; 2019-up Mustang requires B&O.
• Professional installation and system tuning are strongly recommended.

Compatible & Related Products

• PAC APA-TOS1 optical-output adapter - optional digital-output accessory
• PAC AC-LGD - required only for the application rows that specify it
• PAC AC-LGD-60 - required only for the application rows that specify it
• PAC APH-FD01 - required only for the application rows that specify it
• PAC APH-FD02 - required only for the application rows that specify it

Technical Specifications

What's Included

• One genuine PAC AmpPRO AP4-FD21 interface module
• Manufacturer-supplied vehicle connection harnesses shown for this exact part number
• Wired subwoofer-level control and manufacturer-supplied connection leads

Sold separately: aftermarket amplifier, amplifier power/ground wiring, RCA or optical cables, speakers, application-specific APH harnesses, load resistors, and any optional accessories not expressly stated as included.

Fitment disclaimer: Compatibility is not determined by year and model alone. Verify the exact vehicle, factory radio, screen, premium-audio brand, amplifier, connector style, firmware, and application accessories before ordering. Product photos show the listed interface package; surrounding installation equipment is not included. Contact MCOR Automotive through the chat button for application help.

Why Buy From MCOR Automotive

• Authorized PAC retailer with manufacturer-backed warranty support
• Vehicle-specific compatibility help before purchase
• Professional car-audio integration, tuning, and installation support