987/997 radio w/Bose CAI Most Bose HUR adapter Installation

Retain Audio from the factory Bose amplifier when replacing the radio in your 911, Cayman, or Boxster with a factory Bose sound system. The CAI Most Bose HUR module is an interface that converts the audio signal from an aftermarket radio into an optical signal that the factory amplifier can accept.

IMPORTANT NOTE: The bose fiber optic is a two channel audio input, which will result in the loss of the ability to fade to the front or rear speakers only, however all speakers will still play balanced stereo audio.

Vehicles Years Covered: 2005 - 2012

The CAI Most Bose module comes pre-programmed for your particular vehicle and radio. If you ordered your CAI Most Bose HUR module with a radio from our store, the module will be pre-wired to the radio for you. Though the module is pre-wired  to the radio, there are some connections that must be made to the car that are not in the vehicles radio harness. 

Install 997 CAI Most Bose HUR adapter Module 

To simplify installation we have found the easiest and most centralized locations to find these various circuits in the vehicle, including parking brake connection, switched/accessory power, and illumination. 


Kenwood radios will require

  • Accessory

  • Illumination. Note: some Kenwood units have an auto dim feature. If this feature is enabled then this connection is not required.

  • Parking Brake


Alpine radios will require

  • Accessory

  • Illumination

  • Parking Brake

  • Foot Brake 

Some Alpine radios do not have a foot brake or an illumination circuit. If your harness is missing these wires, you do not have to make these connections. 

Notice that some Alpine radios require connection to the vehicles foot brake and that Kenwood radios do not. This connection is necessary for some Alpine radios. If this connection is not made the radio will not allow several functions to operate properly. 

Alpine Radios have an optional VSS (vehicle Speed Sense) connection. This connection allows the navigation to continue tracking the vehicles location in areas where the GPS will not work (long tunnels). This connection is not required for good performance under normal conditions. 

CAI MOST BOSE HUR Installation Instructions 

Tools required for installation of radio and module

  • Digital Multimeter. If you do not already own one of these, they can be found for as little as $20 at your local electronics store.

  • Pliers

  • Wire Crimpers
  • Hook Tool

  • 5mm Hex Wrench (L shaped).

  • Torx (Star) set

  • Philips screwdriver

  • Angle Driver for Philips . These can be found at your local hardware store for about $20. 

Remove the factory radio (See Radio Removal Instructions). 

Note: All circuits should be tested with a digital multimeter to verify identity before connection. Do not make any connection to the vehicle without testing properly. Damage may result. If in any doubt, consult with a qualified professional. 

Mounting the CAI MOST BOSE HUR Module

Remove the climate controls. To do this, simply locate the metal spring loaded tabs on either side of the climate control and press them in with your finger tips while pulling the climate control unit out towards yourself. Unplug and set aside. The module can be located behind the climate control unit. 

Remove the black plastic wire retainer from the factory radio harness and route the orange fiber-optic cables down to the climate control area.*  Take care not to kink the fiber-optic lines. They can snap if forced to bend to tight of a radius. 

Arrange the module so that the fiber-optic lines can be plugged into it and the radio harness can be routed to the radio cavity. 

At this point the radio can be connected to the HUR and the vehicle. Install the radio mounting can and proceed with mounting the radio. 

Tip: cover your center console and shifter with a towel to avoid scratches. 

Plug the red can-bus connector (05-08) and the power connector into the vehicles radio harnesses. 

Connect the RCAs into the new radio. 

Plug the antenna with the supplied antenna adapter into the new radio. 

Plug in navigation antenna, Bluetooth microphone, USB & iPod cables, and satellite radio tuner (if using satellite radio)

* In 2009-2012 997.2 and 987.2 vehicles with 9003 locking harness the fiber optic lines must me removed from the factory side harness and plugged into the new HUR module with the provided adapter, see pics below.

Remove by bending unlock tab

insert fiber into connector and plug into most HUR module


Connect in vehicle wire connections:

There are two locations where Accessory, Illumination, & Parking Brake can be found.

Location 1. Under the small panel below the hand brake.

Location 2 (RECOMMENDED) . Behind the center console structure (not inside the radio cavity).

In most cars these connections are most easily made behind the center console structure. In some vehicles the parking brake wire in particular can be difficult to locate here because it is sometimes bundled with several other circuits. Although in most vehicles this wire is easily accessible. If you have difficulty locating this wire, a wire extension has been included in your kit that will allow you to make this connection at the location under the hand brake.

Instructions for making connections under hand brake (Location 1).

Remove the small panel below the emergency brake. A hook tool makes this easy. The panel lifts up from the rear. 

Under this panel you will find a wire harness that has three of the circuits that you will need to tap into. A hook tool comes in very handy to pull the wires up to a point where the can be accessed (don't force them). It is recommended that you only make the hand brake connection at this point. Additionally, only make the hand brake connection at this point if it proves difficult to make this connection behind the center console as pictured at the end of this article. The connection points shown directly below are only for reference in the event that you have difficultly with the console locations.   

Key-In Accessory

This circuit will supply 12 volts when the key is placed in the ignition switch. This wire is Orange in color. There should be only one of these located under the hand brake lever. Once identified, test to verify that this is indeed the correct wire. 

To test this circuit, ground the negative side of your multimeter and probe wire with the positive side of your meter. This wire should not show 12 volts with the key out of the ignition switch. 

Once you have positively identified the correct wire, use the supplied wire tap to make your connection. 


This circuit will supply 12 volts only when the parking lights are turned on. The wire is Grey with a Red stripe. There are two wires in this area of the car that are the same size and color. Either one works. Test to verify. Ground the negative side of your meter and probe the suspected wire with the positive lead of your meter. Turn headlights on and off to verify operation. 

Once you have positively identified the correct wire, use the supplied wire tap to make your connection. 

Parking Brake

This circuit will supply a connection to ground when the vehicles parking brake is engaged. The wire color is Yellow. It is paired with a Grey/Brown wire and is located just rear of the other two connections that you just made for accessory and illumination. 

Once you have positively identified the correct wire, use the supplied wire tap to make your connection. 

That is all of the connections that need to be hardwired to the vehicle. All other connections are plug and play with the supplied harnesses. 

Foot Brake (Alpine Only)

Alpine radios require connection to the vehicles foot brake in order to establish that the car is parked and not in motion. This circuit will supply the radio with 12 volts when the vehicles brake pedal is pressed. The wire color is Black with a Yellow stripe. Note: this wire will only show 12 volts when the ignition is on. The wire can be found directly at the brake pedal switch. 

Location for Making Connections Behind Console Structure (Location 2).

Once the side panels of the console have been removed you can see a black connector located behind the HVAC controls. This connector contains both Acessory (Orange) and Illumination (Grey/Red) circuits. The plug is in a hard to reach spot. To make things easier, remove the HVAC controls by pushing in on the metal side tabs and then pulling the control box out from the front. Unplug and set aside.

Release the black plug from it's mounting bracket by turning it counter clockwise and pulling it off of the bracket. Once off of the bracket, unplug the two sides of the harness. This is most easily done by putting one hand through the HVAC opening and grabbing the other side of the plug through the side opening.

As you can see below. The plug is visible through the HVAC opening.

Once the plug has been disconnected, you can  pull it out of the left hand side of the console. This will give you much better access to the circuits in this plug.

Hand Brake Connection

On the left hand side of the console you can also access the hand brake wire on most cars. This will be a yellow wire that will show continuity with vehicle ground when the parking brake is engaged. Test before connecting. Note; on some cars this wire is not easily accessible at this location. For these vehicles the connection should be made below the hand brake.


RCA Connections

The CAI Most Bose HUR module has 2 channels of signal input. Connect these RCAs to the RCA outputs at the radio. 

  • White = Front Left
  • Red = Front Right


The factory Bose amplifier derives the subwoofer input from these two channels. No subwoofer RCA input is required.