The HON03-F/MM is a 'Y' harness specifically designed to provide a navigation pass-through on many '03-'07 Acura and Honda vehicles, making it possible to install Auxiliary Input Converters and iPod Interfaces that were previously unavailable for use in vehicles that have the factory navigation system installed. IMPORTANT NOTE: This device is NOT a stand-alone device. It must be used in conjunction with an auxiliary input converter or iPod interface.
In navigation-equipped, late-model Acura and Honda vehicles, the navigation system plugs into the same connector as the connector that all auxiliary input converters, iPod interfaces and adapters connect to. Consequently, if your vehicle has the navigation option installed, in order to connect any other device to your factory radio, you would have to disconnect the navigation to make that connection possible. With this 'Y' harness, the navigation system remains connected and unaffected because of the pass-through feature and will allow the installation of another input device through the other end of the 'Y' harness. So, if the auxiliary input converter or iPod interface for your 2003-2007 Acura/Honda says "for non-navigation equipped vehicles", you can now use this 'Y' harness to install the device and keep your navigation system functional.
IMPORTANT NOTE: If your vehicle has the factory XM installed, you will still have to disconnect it in order to install any auxiliary input converter or iPod interface. This 'Y' connector does not allow XM to remain connected.