Random electrical issue limits power

[BrockWed]

I know trans. failsafe prog. has been covered quite extensively in this forum but my problem is a little different. I got a sub installed and whenever I'm listening to it loud for a long period of time (what I think may be the problem) my dice unit plays music then stops then plays then stops, then my 4x4 light goes on, and then trans. failsafe prog. lights up the dash limiting my power to almost nothing. I always pull over turn off the car and wait, sometimes it wont start right away and act like my battery is completly dead. If I wait another 5 or so minutes my car starts and runs perfectly. I'm going to take it in next week but I was wondering if anyone had an idea of what could be the problem