Harness & Adapters

PAC OS-2 Bose

I wanted to maintain Onstar, factory chimes and have full steering wheel controls. This can be done using the three modules shown on left from PAC.

OS-2 Bose - The OS-2 bose adapter allows you to connect your new headunit to the existing main harness and retain Onstar functionality. For this to work several things take place including the Pac listening on the GM data bus.

This interface will also provide power to the new head unit but its not recommended you do this as most head units draw too much current for the PAC device. Power your new headunit on the input side of the OS-2 interface.

The PAC will not provide VSS signal either (or at least mine didn't). So you will have to take an unused pin/wire from harness and locate it in the unused VSS location on the plug. VSS is used for some NAV systems. My Bose system had a Green wire with white stripe located at pin E on stereo connector 2 for VSS. See here

There is no "illumination" wire at the factory plug either. If your headunit uses the illumination wire then you will have to tap in elsewhere. The rear wiper switch is an easy place to get it. See here.

SWI-PS - This unit allows you to connect your steering wheel buttons (if you have them) to the head unit so you can browse tracks, switch modes, control volume, etc. Your program the unit to match your buttons by going through a short programming sequence. The units green wire connects to the GM data wire coming off the column. See here It's pin A12 (Lt. Green) of the above connector

CM-1 - If you want to retain chimes you need this module. It connects to power and has a pin you insert into the OS-2 harness. OEM chimes are then played through the dash speakers.

Note: You can also use the PAC OS-2 "non bose" version. This will allow you to remove the bose amp. You will be required to manually wire your dash speakers up to this device.

OEM speaker wiring colors can be found here
OEM Bose Headunit plug wiring

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