Dead Sat Port

[williams0517]

I know this has most likely been covered, but I am having trouble finding a response.

 

I have a 2008 Sierra that does not have factory XM installed, and I have two questions.

 

1. Is there anyway to determine if the Sat-port is dead before go ahead and buy a tuner?

 

2. If it is dead, does it have to be activated by a dealer or is there a way to by-pass the dealer and avoid the service charge?

 

Thanks in advance!