HELP!! Radio Swap To Factory Nav - 2008 F250
 

I currently have a 6 disk unit in the dash now. I have the opportunity to trade my 6 disk radio with a ford factory touch screen navigation unit that came out of a wrecked 08 F250 which is the same as mine. I was told the navigation unit works thru the same antenna as the Sirius radio works thru. Is this correct or do I need to purchase another antenna for the navigation part to work? The truck the radio came out of is the same identical truck as mine and it only has the one antenna on the top of the truck along with the standard radio antenna.

Any knowledge of this would help greatly. Thank you in advance!