I bought my 2008 Silverado last year, noticed that I have the xm magnet antenna on the roof. Traced lead to behind passenger glove box.

My radio will not select XM at all, pressing "BAND" button only toggles between FM/AM.

OnStar said vehicle was not equipped, so I guess what I am asking is the magnet antenna above driver door part of the stock equipment and radio it self is messing up? or that an aftermarket antenna to be used with a separate xm reciever?

I called dealership and they dont know what I am talking about.

 

Means someone had an external reciever if it isn't a permenant antenna, in other words factory. I don't think you r factory radio will support xm, the later models, even an 2010 silverado I had did support it, but you had to subscribe. Either contact xm with a request for purchase an external receiver with subscription, or take it to a truck specialty shop.

 

thanks kevin, i have an external sirius unit, i guess ill hook that up for now...

i guess this is a totally different topic, but maybe youd know off hand... i know there is an adaptor to go from xm antenna to match sirius recievers, but cant i just splice the two together? i mean they are just wires right?

 

I don't. You might contact sirrus/xm for what you need.