onstar problem

[bs8621]

I put an after market radio in my 2006 silverado ss along with a pac os-2bose interface. out of the head unit I have rca cables going to a amp. So I wired the front speakers wires up on the interface to the HU but there are wires going to the speakers from the amp also. so the radio works but onstar doesn't. now if I disconnect the wires from the amp to the speaker then the onstar works. Any ideas? Thanks Bryan

[autotoys]

The onstar works through the factory speakers. You need a LINE OUTPUT CONVERTER (search under OEM2), tap into the OS2 output speaker wires and then use those rcas to your amp instead of using the RCA from your new head unit.

Your new head unit is not passing through the ONSTAR and will not pass the onstar volume to the amps