It should tune to 184. Did you already call Siruius set up your account? Even after they activated my account it took about 40 min for me to get all my channels. I guess the obvious is to make sure your outside and your antenna is properly installed.
I did activate Sirius but the unit will not hold a channel. It only displays the id number. If I hold the scan button down, it does run through the channels but when I let up off the button it goes back to the id number in the display.
I checked for kinks in the antenna and everything looks good. I've had XM and Sirius in my previous 2 cars and this isn't acting like it should.