Rockford Fosgate T0

Today my electrical system in my truck like totally failed on me. I have one Rockford Fosgate T0 12 on a Hifonics 1000.1D amp. It's running at 2Ohms so it's getting around 750watts. I have 4GA power and ground wires with 12GA Kicker speaker wire.

Heres a video showing how dim it was going. It has never dimmed this bad before. It use to be just a slight dim which the electrical system only needed like 2 seconds to catch back up with.
https://www.youtube.com/watch?v=QvLO...E&feature=plcp

If anybody knows why this happened feel free to say something. I shut down the truck and started it back up and it seemed to be fine from there so idk. I'm puzzled. BTW sorry for the country music. All my music that I listen to that beats is on my iPhone and I couldn't record a video and stream the music at the same time I guess so I had to throw on the radio and that station was beating the hardest at the moment.

Edit: I did notice however that one of the terminals on my box was hot. I couldn't see whether it was the positive or negative one becuz it was dark tho.

could be a failing terminal causing a slight short which is drawing more current from the amp. i've had those plastic terminals melt on me before.

Well I had a terminal cup melt on me before too. So this time I did some bolt connections.

Melted Terminal Cup
Attachment 26533682
Bolt Connections
Attachment 26533683
It was the bolt on the left that got hot too. Just that one though. The other one was fine.