MstgKillr

iTrader: (4)

There seems to be conflicting information on what is needed to install an OEM nav unit on a non Bose equipped vehicle. Specifically, a 2011 GMC Sierra that came from the factory with Onstar, Bluetooth, reverse camera in the rear view mirror, and remote start but not equipped with a Bose system.

I have read that the nav units do not have an internal amp and will require some type of amp wether it be a factory Bose amp or another external aftermarket amp. Is this true or are there nav units that either don't require and amp or can be modified to work without one? If so, any part numbers or advice? Something about a digital or analog output?

I understand the nav unit needs a GPS antenna to function properly. Since the truck is already equipped with Onstar, does it already have the necessary GPS antenna installed? The reason that I ask, is because I have received turn by turn directions from Onstar in the past.

What exactly is a VSS harness and do I need it?

I understand a used nav unit will need to be programmed by the dealer. Since my vehicle was not originally equipped with nav, how do they properly input the options on the Tech2? What do they input when it asks for an amp?

Any other tips would be appreciated!