Sirius adn Factory Radio Conflict

[wynnamxwell]

My 2005 HSE has an aftermarket Sirius installed and whenever the satellite radio powers up the radio signal nearly (but not completely) vanishes. The satellite radio connects through RF modulation so I cannot see why this would happen. Any advice?

 

[grommet]

Time to talk to your custom installer. Did the installer wire the Sirius RF output into the factory antenna somehow?