Radio control fuse keeps blowing

[bsk9999]

So the radio control fuse on my 2007 ibiza fr keeps blowing up (5amp) but only when i play music at around 30 volume. Once it blows my headunit just turns off (and locks and unlocks my doors for some reason?) until i have to replace the fuse. I have gone through about 10 so far, anyone know what the issue could be ?

 

[qkmstr]

Is there a reason you use a 5 Amp fuse? It came with a 20 Amp from the factory