Audio Systems: Load car stereo noise, watt amps, stock speakers

Question
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Followup To
Question -
 How did I get this noise? 1990 Honda Accord. I have 2 front stock speakers, 2 pioneer 6x9s, a 10" sub, 2 180 watt amps and a crossover. I'm getting extreme noise from every electrical system in the car. It worked fine 2 days ago with the exact same wiring and components. I went in the trunk to clean up the wires and when I turned on the car I could hear this really load noise coming from the back speakers. I checked the ground, power, RCAs, changed speakers, put the amps in a friends car (worked fine), got a portable stereo (worked fine but wasn't hooked into the car's power). What could possibly make this happen? I've re-wired the whole thing 5 times with different RCAs and wires and no difference. The only thing I haven't tried (yet) is take my stereo out of my other car and try that. Any help is very, very much appreciated. This car has never make noise before. Thanks, in advance. Tony
Answer -
Tony,

  try swaping the head unit , alot of problems that "normally" are in the components can be caused by the head unit .. now if that doesnt work and you have checked all the grounds sanded the metal so its shiney and free of paint ect.. stop by radio shack pick up a distortion blocker or noise eliminator .. tell the clerk and they can dig one up for you .. usually 3-10 bucks depending on how fancy you want to buy .. wire this in and it should clear the noise up .. hope this helps you out if you need anything else let me know

thanks

 After I got your reply, I tried the stereo. It was the stereo for some reason. I bought a new one and put the old one in my wife's car. Works fine through only the speaker wires and no amp. What would make only the RCAs break? I shorted the amp for a 1/2 sec installing it.

Thanks again,
Tony

Answer
Tony,

 its really a strike on chance on new units , and fairly rare on units with a few years of use on them .. the short shouldnt have affected the RCA's .. most common thing that happens is the preouts "burn out" i'm not an internal mech on stereos but that is what it seems to me the same thing happens to VCR's DVD players ect.. even in home theater equipment.. but glad to know you got it back up and going

thanks