if i change out the factory head unit to a alpine unit still using the bose speakers will that effect anything in the nav system?

 

You might lose the navi voice, unless you know how to mod the new HU so that you could feed the sound output from the Navi.

 

Davey I am doing this now. I have already tested it b4 I installed an closed every thing up.

I used 2 27D. 1 for the onstar mute and 1 for the nav. I routed the audio from the Onstar unit to a clarion center channel speaker installed in the 1.5 Din slot. This all works like a excellent.click here for the relay site

 

thanks for the info.