I have a NBN 1200watt 2 chanel amp, a 12" plye 1200watt sub, A jvc headunit. I had to unplug head unit the other day to get into the air con, I pluged it all back in exactly the same, Then i left and noticed the sub wasnt working and neither was amp, So i re wired everything from battery to amp to sub, still nothing so i tested volt meter, at the bettery 12.44v and at sub 12,43v and when i turn car on i get 4.67v at amp, so im guessing that there isnt enough power getting to the amp, so it wont turn on, i have checked everything i can think of, replaced all fueses even, Please help me