I agree with Pancit's first statement, to eliminate the amp from the equation run your power cable directly to the +12v input on the amp, and ground the amp somewhere close (within 18"). Next, create a short jumper wire from the remote to the same 12v input. If possible, do all this close to your battery to eliminate any cable flaws in the run. Here is what I mean:
If the amp doesn't go into protect mode like this then it is fine and the flaw is in the cable runs... or the cables themselves. what gauge wire are you using?
As for his second statement, I couldn't disagree more. The question is in the proper topic, to the point, and genuine. This is exactly what this forum is here for. I don't care if you are planning (or have) a PC in your car or not.
Grey