i'm stuck

Professionally installed? Then why did they leave you hanging?

All audio cutting out sounds like a loose harness connection into the back of your radio. You have to really press hard on the plug until you hear it fit in -it makes a sound when it fully plugs in-. I'd check there.
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That would be my guess as well. Check all the connections on the back of your head unit to make sure they are secure.

When I installed mine I had a similar thing happen. I had the wiring harness unscrewed and pulled off to the side so I could get to the head unit. I plugged in the SAT interface and everything worked fine... until I put the wiring harness back in place and screwed it in. It turns out the main interface cable was aligned so that the wiring harness would loosen it from the head unit when I put it back in place. It's a tight space with not much room to orient the cables so that they don't pull on each other.

 

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I got lucky. When DIY-ing my head unit(wait, that sounds bad - lol), I was reinstalling it, but something made me stop and mess with the plug one more time.
In doing so, I was pressing on it hard and it clicked (fully seated) into place.
Big phew when that happened. I was thanking my stars. Otherwise there would have been a lot of curious/frustrated troubleshooting as I had thought it was already properly in place.
Now I always listen for that soft click.
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