chaseton:
In an ideal situation with no music playing there’s no voltage on the outputs of an amp. When you short an amp in this situation you should generate no current.
If your fuse blew it _might_ be an indicator that there’s some DC offset. Meaning that instead of an amp returning to 0V it returns to some value above or below 0 that is significant. Get a multimeter, set it to DC and measure. Value should be under 100mV.
On the other hand, an amp could short from just it’s normal noise.