I'm having a problem with the satellite radio in my '08. I bought the car used and immediately changed out the XM the receiver under the waterfall to Sirius so all three of my vehicles would have the same service. I know the Vette isn't the best at receiving radio signals, but its way worse than the stock systems in my '08 F-150 and '08 Expedition. It’s to the point that my wife thinks I should cancel the subscription. With the Fords I can pass under an overpass without loosing anything. The Vette will continue playing until the buffer runs out then will cut out for the length of time it took to go under the overpass. Sometimes it seems to cut out if I drive through the shadow of a tree, or under a power line, and when I cross a bridge with a steel super structure overhead its like having a bad AM signal. The Fords do none of this when driving the same roads. At first I thought the factory antennae connection was loose, checked it, no luck. I installed the antennae that came with the radio and put in under the tonneau cover, no improvement. I stuck on top of the tonneau cover, outside the top frame, no better. On certain bumpy roads I get “no signal” on the display. I even get the “no signal” when I go over the curb at the end of my driveway to hard. Add to that every once in a while I get a “satellite radio failure” message when I start the car. Turning the radio off then back on usually cures it, but sometimes I have to do it more than once. The cutting out on bumps sounds like a bad connection. I’ve checked the plug at the module and it’s good. Are there any other plugs, other than the one at the back of the radio, in that system? Do I have a bad Sirius module or is something else wrong?

 

Is it the SIR-GM1? It may be a bad one. I just put one in my coupe and the only thing I've noticed is it does have the loss of signal under a bridge. Other than that I don't have any of the other things going on that you do.

 

I have Sirius in my 2003 Acura and it does many of the things that your car does.

Definitely goes out under underpasses and also goes out any time the satellite signal is blocked, say when I am at a drive through and close to the side of a building, in a car wash, and sometimes if the trees are really thick with folage.

Sometimes it will keep playing if you are getting a reflecting signal from some other object close by. I have noticed that if I am setting in a car wash close to a road, occasionally the radio will reconnect briefly when a large truck goes by.

The Siruis radio is only going to work if it can receive that signal some how. I believe that the way some vehicles are built makes them better 'receivers' than others, especially better than the Corvette since it doesn't have a metal body.

 

Are you using the factory antenna or the one that came with the car? I was at the post office this morning and the thing lost the signal for about 15 seconds and I wasn't moving and was in the middle of parking lot.

 

The one that came with the car. I have an '05 and it's the wart on top of the roof.

 

When I was still using the oem radio and SIR-GM1 (with car antenna in mirror) my signal would drop out sometimes in expected locations (bridges, between tall buildings), but would also become almost unbearable sometimes for a day or so at a time even on the open road.

After switching to new HU and aftermarket sat antenna mounted in dash it got slightly better with the 'expected' dropouts, but when I lose my signal it's GONE! In a day or so everything is back to normal.

I believe the issue with SIRIUS is the way their satellites rotate above North America. If one is currently passing over you, no problem getting signal, even in downtown areas. However, if you're "between satellites", just switch over to the ipod for a few days.

 

I was thinking and going to say that same thing but he said his Ford's have no problems at all with dropouts so who knows?