Here is my problem,

I recently installed 2 12" infinity subs and a 611a infinity amp. Wired in myself and seemed to go well, followed all the advice on wire guage (4 guage) and fuses and such. I got the amp running and after about 20 minutes of pretty moderate usage it switched into protect mode, after a short while of the truck being off I turned it back on and it came on normal and played music. Now it will go into protect mode for a couple of seconds and come out again, very confusing. I have checked the ground and it seems ok, the woofers are both reading 4 ohms which is normal. I tested the voltage and it seems ok (just above 12v) the only other thing I can think of is the remote wire from the HU but I don't know how to fix that problem. I was wondering if anyone has any insight or advice. Also is it possible for the voltage to drop during normal driving and is there anyway of fixing this problem.

Any help would be appreciated.