Fuse rating for stereo

[jim.powell@xxxxxxx]

     Harvey said or quoted:
     
     >>>
     4 gauge wire and special 80amp fuse
     
     So, do any of you guys/gals have any thoughts?
     <<<
     
     The above was severely snipped....
     
     
     I just have one thing to add to Harvey's generally excellent writeup.
     Think about this, my '98 M3 has an 80 amp alternator.  I am running 
     600 Watts of stereo amplifiers.  Plus lights, air conditioning, the 
     actual ignition system, etc.
     
     Harvey is right.  None of these things pull peak DC current full time 
     except the lights.
     
     I have gauges in my car.  If I only have an 80 amp alternator and I 
     have all of these high amperage loads on at the same time, I should 
     see the Volts gauge drop below the static supply voltage of the 
     battery as it trys to make up the shortfall from the 80 amp 
     alternator.  I don't.  Not ever.  So this is a very long way of 
     proving you don't need an 80 amp fuse because your car probably only 
     supplies ~80 amps.  Its not all going to your stereo obviously.  Fuse 
     it at 30 amps and tell this kid to pound sand.  8 gauge wire is 
     overkill.
     
     Jim Powell

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