96 suburban radio trouble???

I JUST RECENTLY BOUGHT A 96 SUBURBAN THAT HAD FACTORY RADIO,I INSTALLED A AMP N SUBS AND A JVC RADIO,A FEW DAYS LATER THE INSIDE SPEAKERS STOPED BUT THE SUBS STILL WORKED, I TRIED ANOTHER JVC AND SAME PROB,I THEN PUT THE FACTORY RADIO IN THE VOLUME WOULD BE VERY FANT THEN YOU TURN IT UP AND IT WOULD GO FULL BLAST.I THEN FOUND OUT ABOUT THE SCV ON THE FACTORY RADIO N A WIRE FROM THE SPEED SENSOR WENT TO THE HARNESS. I THEN CUT THAT WIRE THEN TAPED IT REAL GOOD N PROB STOPED FOR A DAY. IM WONDERING IF MABYE A SPEAKER WIRE IN ONE OF THE DOORS IS LOOSE N CAUSEING IT TO SHORT,THE WHOLE TIME I HAD THE AFTERMARKET RADIOS IN IT THE SUBS STILL WORKED BUT NOT THE 6 INSIDE SPEAKERS. WIREING TO AMP I RCA ARE GOOD AND THE FACTORY HARNESS DONT SEEM TO BE SKREWD,I GOOGLED THIS PROBLEM AND IM NOT THE ONLY ONE WITH THIS PROB,NOW WITH THE JVC IN IT THE SPEAKERS WORK BUT CRACKLE THEN THEY JUST GO OUT ALL OF A SUDDEN? ANY IDEAS BEFORE I TARE MY DOORS AND DASH APART.... PLEASE HELP........BERT