Why Choose Crutchfield?
Great gear and expert advice
Our experts help you pick the ideal gear for your needs.Meet our advisors
Free tech support for the life of your gear.Read about our one-on-one expert help
You may return items that are complete and like new for any reason within 60 days.See the details of our return policy
Earn one point for every dollar you spend and use those points to save on future purchases.Get full details on Crutchfield Rewards
Deep discounts on car installation gear
We offer vehicle-specific installation instructions, dash kits, wiring harnesses, and speaker accessories at deeply discounted prices with car stereo and speaker purchases. Available for most vehicles.Learn more
Trusted since 1974
Our customers have trusted us with their business, and they’ve helped us win awards for our service.Check out our most recent awards
The manufacturer’s warranty always applies.See more details
PAC AMP-GM21B Pontiac Factory Integration Adapter
Required with OS-1 Bose Interface for 1999-02 Pontiac Grand Prix to retain OnStar® and Bose® systems
Our take on the PAC AMP-GM21B Pontiac Factory Integration Adapterby Crutchfield's Robert Ferency-Viars
Pacific Accessory Corporation's GM21B harness works in conjunction with the OS-1 BOSE adapter to allow you to replace a GM radio (without RDS) in a 1999-02 Pontiac Grand Prix. You can install an aftermarket receiver, and still maintain operation of the OnStar® system and the GM Bose® amplifier and speakers. Warranty: 1 year.
Important Note: The GM21B harness and OS-1 BOSE adapter will only interface with 1999-02 Pontiac Grand Prix radios that do NOT have the "RDS" option. If there is an "RDS" logo on the radio face, the harness and adapter kit will not work. In order to determine compatibility with your vehicle, please use the vehicle selector on our site, or call a Sales Advisor at 1-888-955-6000.
Note: Most vehicles will require additional installation parts please identify your vehicle if you haven’t done so. You can also call an Advisor for more information.