01-04 MB Acc and NAV OUTPUTS - Retains R.A.P. and NAV Outputs

Our review of the 01-04 MB Acc and NAV OUTPUTS finds it best for installers who need to retain vehicle accessory functions while adding navigation outputs in Mercedes-Benz models. The module's single biggest reason to buy is that it delivers retained accessory power plus dedicated NAV signals without requiring a factory amplifier, making swaps or upgrades cleaner and more reliable. Practical for technicians and experienced DIYers, this review focuses on real-world fit, wiring convenience, and how those NAV outputs behave when integrated with aftermarket head units.

Key Features

• Accessory Power: Supplies a 12-volt 10-amp accessory feed so aftermarket radios receive stable power without overloading factory circuits.
• Retained Accessory Power: Keeps R.A.P. functionality intact so accessories remain powered for the expected post-key-off interval.
• Non-amplified Use: Designed for non-amplified systems or when replacing an amplified factory system to simplify installation and avoid amplifier integration issues.
• NAV Outputs: Provides parking brake, reverse and speed sense outputs so navigation and safety interlocks work with the new head unit.
• Pre-wired Harness: Ships with a pre-wired AXSWC harness configuration to speed up wiring when the corresponding harness is available.
• Updateable: Micro-B USB updatable for firmware or compatibility fixes without swapping hardware.

Who It's For

The module is aimed at vehicle electronics installers and knowledgeable DIYers working on 2001-2004 Mercedes-Benz models who need to retain accessory power and provide NAV signals when fitting aftermarket head units. It particularly benefits jobs where the original system is non-amplified or where an amplified system is being replaced and amplifier integration is undesirable.

Those who should look elsewhere include owners who lack wiring experience or installation resources, and anyone whose vehicle requires a bespoke amplifier retention solution; this unit assumes the installer can match the AXSWC harness and manage CAN or speaker-level connections as needed.

Pros & Cons

Pros

• Restores 12V accessory power at 10 amps, preventing accessory underpowering with aftermarket radios.
• Maintains R.A.P. so convenience features tied to retained accessory power remain functional.
• Supplies dedicated NAV outputs including parking brake, reverse and speed sense for proper navigation behavior.
• Micro-B USB updateable and pre-wired for faster installations when the matching harness is used.

Cons

• Requires the AXSWC harness (sold separately) which adds cost and another compatibility check to the install.
• Not intended as a plug-and-play option for users without wiring experience or access to professional installation tools.

Specifications

Product Type	Accessory and NAV output module
Accessory Power	12-volt, 10-amp
R.A.P.	Retained Accessory Power supported
NAV Outputs	Parking brake, reverse, speed sense
Compatibility	Used for 01-04 Mercedes-Benz models (non-amplified or replacing amplified)
Harness	Pre-wired AXSWC harness included; AXSWC sold separately
Firmware	Micro-B USB updatable

Our Verdict

The 01-04 MB Acc and NAV OUTPUTS is a practical, installer-focused solution for retaining accessory power and adding navigation outputs in older Mercedes-Benz vehicles. It offers sensible features like a 10A accessory feed, R.A.P. retention and updateable firmware, making it good value for professionals and competent DIYers who can source the AXSWC harness and handle wiring.

Frequently Asked Questions

Does this unit retain the vehicle's RAP functions?
Yes, it retains Retained Accessory Power so accessories remain powered after key-off for the vehicle's standard interval.

Are NAV outputs included for parking brake and backup detection?
Yes, it provides parking brake, reverse and speed sense outputs required by many navigation units.

Is the AXSWC harness included?
The module is pre-wired for the AXSWC harness, but the AXSWC harness itself is sold separately and must be obtained for a fully plug-in installation.