Check your intercom VOX. (voice activated switch)
Turn it off, or at least turn it down.

If it is on, or set too sensitive, it cuts out the radio so you can say, "did you see that deer I almost hit?"

 

Thanks for all the suggestions. Dealer replaced radio. They said it is not an uncommon problem. Cecil

 

Well I finally got around to taking my bike to the dealer, replaced the radio and it seems to be working for now.

I guess the rear volume only works on the headset, I was thinking it worked on everything.

 

On my 2009 Ultra, I hear a loud SNAP and the radio is still on and lit but all four speakers turn off. I turn the radio off and back on and that usually starts the speakers.
I can listen to my head sets with no bike speakers on and they never shut off, something in the amplifier for the speakers maybe? Any help or suggestions would be appreciated.

 

Had the same problem on my 08 Ultra. Turns out the bolts that clamp the handle bars are too high and hit the bottom of the radio causing vibration damage. Mine had 2 small dents in the bottom of the radio that confirmed. Harley has a new designed bolt head. I just ground mine down a little. But the damage was done. It will get worse. I pulled mine and sent off to Iron Cross and they put a new board in. They also put RCA line outs for an amp while they had it. Everything is fine after 2 years. I was out of warranty so that was only option. Good luck

 

Had the same problem on my 08 Ultra. Turns out the bolts that clamp the handle bars are too high and hit the bottom of the radio causing vibration damage. Mine had 2 small dents in the bottom of the radio that confirmed. Harley has a new designed bolt head. I just ground mine down a little. But the damage was done. It will get worse. I pulled mine and sent off to Iron Cross and they put a new board in. They also put RCA line outs for an amp while they had it. Everything is fine after 2 years. I was out of warranty so that was only option. Good luck

 

I had same problem. They had to replace the radio.

 

My '13 RGU does the same thing. Going to take it in and have them check the radio. Seems like a common issue.

 

I found on my bike after removing the fairing and unplugging the radio wire plugs to repair a broken fairing mount that the radio started working again so the problem was with one of the multiple plugs. Works great now.

 

Good Afternoon... On my 2012 Ultra, I had the issue with the radio sound cutting out intermittently. It would play sometimes for two hours, three hours, or five minutes, or ten seconds and then cut out. If I switched the three position rocker on the lower dash back and forth it would come back on. Sometimes I would have to move the switch back and forth several times, and sometimes only once to get it to come back on. I was sure it was the switch. I took it to the Dealer, and after testing, it was NOT the switch.. It was the radio. Even though the switch would bring the sound back.
I took it in to the Dealer because I had the Extended Harley Warranty (ESP) and the Dealer replaced the radio. Otherwise I would have done something aftermarket. This is the second radio that has quit in some way. Just as info... Ride Safe!