ignition timer killing rca converter

i have a 2001 pontiac grand am gt with a factory monsoon sound system. i tried to replace it with my jvc head unit, after hooking it up, i notice that only the subs would work but not the rest of the factory system. so when i couldnt figure it out i broke down and took it to a car and audio shop and they told my factory speakers were fried and when i got home took out the jvc and put back the monsoon and everything worked fine. i called them and they didnt know why. a guy i worked with told me something like those speakers only work with that paticular head unit and vise versa. could this be? so i purchased a couple of rca converters to tap the factory speakers and then every time i would turn the car of since the radio would stay on after the ignition turned off it would blow the converter. i thought maybe since it was from wal-mart it wouldnt take the abuse so i purchased others and they all do the same. has anyone else had this problem? what am i suppose to do?

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One fist like a rock, the other made of steel. If the first one dont hit you the right one will!

You may want to get output off amp output side if using a line out converter. Or use low output off back of radio through rca cables that have been spliced into wires (only attempt if you have knowledge of what you are doing)
After market radio needed a different acc. source. The OEM circuit doesn't provide a switched one. I would find one at ignition harness to sort out the confusion. If new JVC radio had RCA out for front and rear, that is what would be used for input of OEM amp. Also make sure factory amp is getting 12v switched from power antenna out off JVC unit.
   
Battery          ORANGE          (+)          RADIO HARNESS     
Accessory THE RADIO HARNESS DOES NOT PROVIDE A SWITCHED POWER SOURCE.     
Ground          BLACK/ WHITE     (-)          RADIO HARNESS     
Illumination     GRAY          (+)          RADIO HARNESS     
Dimmer          BROWN          (+)          RADIO HARNESS     
Amp Turn On     PINK          (+)          RADIO HARNESS     
THIS WIRE IS USED TO SUPPLY POWER TO THE REMOTE TAPE OR CD PLAYER IF EQUIPPED.     
     LF Speaker (+)          TAN     
     LF Speaker (-)          GRAY     
     RF Speaker (+)          LIGHT GREEN     
     RF Speaker (-)          DARK GREEN     
     LR Speaker (+)          BROWN     
     LR Speaker (-)          YELLOW     
     RR Speaker (+)          DARK BLUE     
     RR Speaker (-)          LIGHT BLUE     
Amp Location          MOUNTED BEHIND TRIM IN LEFT SIDE OF TRUNK     
Steering Cntrls          OPTIONAL     
Speed Cntrl          OPTIONAL     
Radio Security          YES

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The wire I'm test'n isn't doin' what it's supposed to be doin'... I am so glad I printed that tech sheet, with the wrong info.
Do it right the first time... or I might have to fix it for ya