had this brfore with a monobox 4 amp on my old 306 turned out it was the battery

it would run for a little bit and then cut out and go into protection mode, then when i ran the car and started it again it would do it al over again! my battery wasnt great and the amp just killed it!
your wiring will be fine it just means ure not going to get the best out of the amp as it cant suck enough power to run full but wouldnt cause it to cut out!
the only other thing to check would be the earth as said in above post. the beat place for an earth is a seatbelt mount clean it of all paint and tighten the earth (dont forget its alot of power to get rid of)
personally if its not a good earth then that will be ure problem but if you know thats all good then id check ure battery!
hope that helps
cheers
luke awesome.audio