I have an 04 coupe with factory radio with very poor reception. I recently had the head liner replaced and thats when the problem started. I'm pretty sure the connection to the "black box", under the rear window covering is the problem. the plug from the two wires connecting the window antenna does not "feel" like its making a good conection. I guess my questions are; 1. What is that box called and what's it's function? 2. Can I bypass the box? 3. How can I check if the box is functioning correctly?

Thanks for the help.....