Amp shutting off going into protection mode

sounds like output transistors proffesional repair time sorry

Check all your fuses and make sure your ground wire is properly grounded you can put it right on the neg side of your battery to test.

check powers and earth, unplug sub and crank it up see if it still goes into protect if it doesnt the sub is too much load for that amp and could have damaged the amp, if it still does it then its a fault in the amp or power problem make sure you have good thickness 4gauge and good earth

Is that on all the time or are you saying the light is on? If that light is always on that just means it's protecting your amp. If it's off and not playing bass then your in trouble

The amp is being overworked and is overheating so it is shutting down to protect itself. You could try to add a fan and point it at the amp to help keep it cool. Also make sure the amp is not located where it will get heat from an exhaust pipe under the car for example. They may have external fans that you can attatch to the amp to help cool it. The constant overheating could eventually damage the amplifier.

My amp stays in protect mode i don't know whats wrong Any suggestions

need a bigger gauge hot wire going to your amp ,maybe a battery cap. amp isnt getting enough power to perform so it cuting out.

Check and see what size fuses it uses. Your watt power means nothing without good fuses. My suggestion would be to go buy 40a fuses and replace the ones you already have.

Theres most likly an open ground printed circuit trace on the Printed circuit board on the bottom. first clue is You said your girlfriend disconncted and blew the fuse. You gonna have to ytake the amp apart and totally disassemble the PCB off the rails and everything unless theres a bottom cover. It may be an obvious burn or could be hidding under the green paint of a trace?? Goos luck