amp turning on and off?

Hi guys. I have a 2009 Mitsubishi Galant with the standard radio. I installed an amp a few weeks ago. A lot of times, the amp will turn off or won't come on at all for a few seconds- up to a minute sometimes. The protection mode light doesn't turn on though, it just completely turns off. And I can have the volume up or down, it doesn't seem to matter. I used a voltage meter at the power, ground and remote wire on the amp and it seems to get voltage- though my meter only shows a lightning sign, not an actual volt rating. And I checked my wire connections again.
Does anyone have any ideas?

FYI- specs: Power Acoustik OV-840 supposedly 4x80w rms (it only has a 40a fuse!), 8ga kicker wiring kit, polk db 651 up front 55w polk db and polk mmc 690 rear 100w rms

Those amps are notorious for having bad connections that will cause the problem you are having.  Next time it turns off for an extended time, leave the volume up and first wiggle the fuse on the amp.  If that makes no difference, grab the terminal block at the power remote and ground wire and move gently up and down.  Then if none of that makes it play, the bad connections are probably on the rectifier diodes.  These are not easy to get to, but if you can get me a picture of the inside of the amp, I can help you get it apart and repair the bad connections.

Thanks 'I am.' I'll try those methods and see. I'm at work now so I can't right now. I'll work on it tomorrow. I did notice that the fuse felt looser than I expected when I was installig the amp though. I just moved it a little to see how sturdy it was. I guess there really is no getting around it with car audio- you get what you pay for. Thanks for the help.

Thanks again I am! I really hope that's the extent of the problem.