[mikegett]

I am not familiar with the triggers. Could you describe them? Give a part number we can look up as well as the directions for installation. From what I am getting, it allows the speaker wire to activate the amp. If so, I wander if you have the power and speaker wires switched on them. It will probably have a sensing connection that goes on your speaker wire to activate. There will probaly be a 12 volt supply like you stated and one 12 volt going to the amp to turn it on. I would be curious if you have the 12 volt supply and the 12 turn on switched. Just a guess. In order to tell if your amp is the problem, look at your power light. There will always be a light that stays on with power. Sometimes, there is a light that activates when the amp goes into thermal protection like bigd was saying. If the volume increase turns off the amp and power light then look at your connections or trigger. If the power light stays on but the amp shuts down then it is internal in the amp or a bad LOC. The little light is used in this manor for diagnosing potential problems.
Since you stated that the LOC was unplugged with the same results, I doubt it is at fault. My guess is in the trigger. A quick way to check this out would be running a 12volt wire straight off your amps 12 power source. If the amp stays on then the trigger is at fault.