I think the best way is to get it inspected in person. Hard to find a correct solution if not enough info is given and it could be many possibilities that causes the the cut off. For god know could be a faulty unit ( knock on wood). But the way I have show you is to eliminates possible causes. IF you have wired the Speakers directly to your Unit. Then it is possible that the unit could over heat from high volume. Factory Unit inbuild amp is not that strong. Plus I dont know what size is your speakers or how many is hook up to the unit. Some unit come with inbuild thermo protection that cut out the power when overheating to save your Unit from melting up. When the unit turn off so will your amp. Unit have the remote wire link to your amp unless you have wired differently.
Incase of over heating then best way to solve is buy a 2 or 4 channels amp and use that to run the speakers 2 or 4 speakers and have the unit free of heat and produce better signal to the amp. *better sound from amp anyway , louder, stronger, clearer and more control.
good luck this is my last post for this topic.
Yeah Sorry We're not expert like some in here. cough cough...
Ok guys non expert packing up and leave.
I am packing up and leave now.