amp wiring

[Supra2NR]

ok i am stumped

i have installed
single amp, dual subs
dual amps, triple subs,
triple amps, triple subs
triple amp, dual subs, interior speaker combinations b4

now i am trying to install
this is the most simplest setup i have ever did
a single 12 single amp setup in my mk3

but the fuse keeps blowing out
i have a sony xplod 1000 watt 2 channel amp
with a 12 inch xplod sub
i got an inline fuse (30A)
the two fuses in the amp are 30A too

everytime i put the fuse in it blows
ive tried:
taking the power wire from the battery, put the fuse, when i put it the power back in it blows
took the ground wire from the battery, put the fuse, when i put it back it blows
tried the same thing with the power wire from the amp, same thing happnd
tried the same thing with the ground wire from the amp, same thing

i have went thru a whole pack of fuses already i am stumped and frustrated

any help will be appreciated