I'd start by checking my wires and make sure no copper wires are exposed etc. My brother has a cheap stereo that barely works but its all connected correctly if he turns off his vehicle without turning off the power to the stereo he has to pull it out disconnect the power for thirty seconds or so and plug it back in to get it working again. If that stereo what came in the car It might just be worn out and time to get a new one. Also I blew a 3 inch speaker in one of my vehicles on a pioneer stereo and I guess the stereo has some sort of self shut down to prevent blowing fuses or something. While that speaker was blown I could only turn up my stereo to ten of about fifty If I went over ten my stereo would shut it self off. Try Leaving the volume at a lower level then you normally listen to and see if it stays on.
