Quote Originally Posted by simbah View Post
The harness you have noted will not work with the Monsoon system, as it has an amplifier that is separate from the Head unit. The harness you are looking for is the GMOS-04

Amazon.com: Axxess GMOS-04 Class II OnStar® Interface for Amplified Systems: Car Electronics

this will retain all the chimes for your vehicle, and work with the external Monsoon amp.
thanks for the response, thats exactly what I was looking for.