Ok i have the GEX-5700tv tuner installed on my D2 but when i go to install the sirius tuner my unit will not recognise it being there i have tried several diff configurations but i plug the bus cable from the outut on the sirius tuner to the bus in on the tuner and that is all correct???

Is the cable the correct way? ie, blue to blue, black to black.

I have no clue if this matters, but its worth checking.

You can also try switching the Sirius and TV tuner in the order.

Put the TV tuner into the input of the Sirius and the Sirius output into your headunit and see if that works.

By the way, how do you like the tuner? Do you find that you have good enough reception to actually watch tv?