Head unit shuts off?

I have an Alpine 9855 and recently it keeps on shutting off if i go past a certain volume. It started when i recently hooked up an amp for my sub. I thought it was from that but when i disconnect the amp it still cuts off after a certain volume. When i installed the head unit i had to move the radio wire on the fuse box to a different fuse slot because the radio fuse was messed up because it had a loose wire some where and kept on shutting off, but it didn't do this. So can anybody help?

Sounds like you have the same problem with the new deck as the old.  The Alpine pulls a lot of power - are you using it to power speakers?  I'd first try a new ignition & B+.

Changing it to a different power source worked. Thanks a bunch