I have been following this thread here and i was wondering if someone can help me:
https://chevroletforum.com/archive/t...oe-5604-7.html

I ordered the JP Customs kit, but i received nothing for the Onstar hookup. Its not even in the instructions. How do you ensure that the Onstar hookup works perfectly?

 

If you already have onstar, then it will work with the nav unit once it's programmed at the dealer.

 

But don't you have to connect those two wires from the onstar box to the back of the radio? I have a 6 Disc changer now, is this already done for me?

 

I installed a factory nav unit in my tahoe. The silverados are wired the same. You dont need to connect those wires for the onstar to work. The onstar will work just like it used to with the 6 disc changer without the onstar connection from the Nav radio to the Onstar box. You can control the onstar speaker volume with the nav volume control on the unit itself and hang up by pressing the down button on the steering wheel. The phone book in the nav unit works and the turn by turn voice directions will work without it too as long as the VSS control wire is connected. The only thing that will not work will be the voice command features. It uses the onstar mic for the voice controls regarding the radio and the navigation functions. I have the wire hooked up but it takes more time to get it into voice command mode (almost 8 seconds) than it does to just change the station, select CD or radio, or choose your destination by using the buttons. I never use it. Hope this helps.