some help needed
 

Okay, I have a 99 blazer zr2. Does anyone know if they came stock with the bose? And if so, is there anyway to tell? I have tried 2 new head units. One pioneer and one alpine. Heres whats happening. The speakers work great. but at time atleast once a day while your driving it, all the speakers in the truck with get real statiky and then they'll fade out and ill have no sound at all. And it will stay that way till i shut the truck off, then its a 50 50 chance that they'll work again. Its been happening with both radios. I tried hooking an amp up to see if it helps but its not. It seems like the front speakers are getting way more power. I can barley hear the back ones but the fronts are good and not blown. I checked them myself, Do you guys got any ideas on what it could be?

It could be a bunch of things. Does/did your....
1) radio turn off also?
2) antennae adapter fit into the radio correct or does it hang loose?
3) stock radio ever do this or anything weird? like speakers popping, bad distortion or fade out?

It could just be something simple as the antennae adapter not fitting right, or the wrong one, a bad ground in the radio (something i've seen before) or something overheating for some strange reason