Been riding a Sportster for eight years. Traded for a Ultra Classic with a few issues. The Radio turns on and has all controls that work but get no volume out of it. I degreased the engine and pressure washed under seat a while ago after that the radio worked for about three hours then went back to same issue. Pulled fairing off checked all connections hooked another known good speaker to radio still nothing. There is a amp under tour pak that im suspicious of . If anyone had the same issue give me a shout.

 

Sure sounds like a bad connection to me. Likely, under the seat or at the Amp. I suspect that some water got in when you washed it and completed the circuit until it dried out. It might be the power to the amp rather than the lines to the speakers.

 

my 2008 radio mother board cracked .the fairing brackets were cracked vibrating the radio .everything went on just no sound. This was on a 2008 Electra glide. I would guess its common as I bought brackets off of ebay to fix the fairing.

 

I would be suspicious of a bad connection at the amp as well. You can always unplug them and look for corrosion. Sometime just unplugging them and then plugging them back in will get it working. Other times it could be a broken wire that requires taking the connector apart it inspect it for broken wires.
In any case the radio it your bike was made by a different company than everything since 06. For service for the radio or amp itself you will need to go directly the the manufacturer. and that company is Radio Sound in Louisville, Ky

http://www.radiosound.com/customer_service.php

 

try it with the head set also make sure that your cb is not on

 

Hate to say it but the old radios were very unreliable. Replaced my 2006 once, replaced the 2010 twice. The problem is that there is a hard connection between the internal amp and the head unit. After 30,000 miles or so it vibrates and breaks the connection and you lose volume. It will crackle a few days or a few weeks then eventually separate completely and give no volume.

Now I have a 2014 Limited and it crackles from mile one! These radios are made by Harmon. The new radios have similar hardware and software as the radios they sell to Chrysler /Dodge/Fiat.....and Ferrari and Viper. It was just adapted for Harley use. Harmon owns some of the most high end stereo brands in the world. It must be embarrassing for them to not be able to make a decent motorcycle radio......twice. But I have faith they will get it fixed.