So ever since I have installed my new sub and amp, every now and then they cut out for about 5 seconds. My speakers come back on, then my sub kicks in a few seconds later (I have 2 amps; 1 for speakers and other for sub). Then I also have this problem where they don't work at all sometimes. If I connect the positive and remote wire from my mono block amp together, the sound system works again. I don't have them up loud, they seem to be doing it at random times.

Any help would be great.

Check your trigger wire connection. It may be jiggling loose, making a bad connection.

havee you tried tracing back all your wiring to make sure there's no shorts or cuts or anything?
also make sure all your connections are strong, your earth is good and you've sanded back to bare metal where you've earthed it to.
always best to just check everything over, that way you canuse an elimination process.

whats the rms output of the amps?

does it do it at a particular volume, or type of song (bass, techno etc.)

I'll be checking the positive and remote wire first to see if it's being pinched anywhere. All the wires are on the amp terminals nice and tight, and the back of the head unit, although I'll double check there again.

If this helps, my 4 channel amp's remote wire is connected to the mono block's remote wire terminal so they are linked, which then goes to the head unit.

I never bothered to properly sand it where the ground wire goes to, but if one of them isn't making proper ground, would both amps still cut out?

My Rockford P3 sub and Pioneer mono block amp are rated at 600w rms each. And no seems to happen at any song or at any volume. Which is weird.