If your protection light is on the you have a short somewhere. Check your power cable and remote turn-on wire to make sure that there is no bare wire touching any ground spots. Also, make sure that you connected power to power, ground to ground, and remamp to remamp on your amp.

Maybe you accidentally screwed into a wire or something. Either way, that's what the protection light is for. It's going into protect mode because it's shorting out somewhere. Check all wires!!!