pa1100.5 shutting off in an 06 charger

Hello, as I said I drive on 06 Dodge Charger with a factory headunit. My setup is as follows: Polk Audio PA1100.5 Amp 1 Alpine Type R 12" Sub alpine 6x9's in the rear alpine 6.5 type s components up front Everything has worked fine for about 4 months. Then about a week ago I had 2 problems develop. First, the sub has stopped working. It doesnt hit at all. Occasionally it will make a very faint rattle noise that I can only hear if I am in the trunk and about a foot away from the sub. My second problem is that the amp will randomly turn off if I have the headunit volume over 10 (The volume starts at 0, and I have the gains set so that it peaks out around 32 or 35, so 10 is not very loud). When the amp shuts off, the LED on the amp turns red. It will only shut off for about 5-10 seconds and then turn back on. But it will turn off again about 30 seconds later. And the cycle repeats. Any ideas on what the issue could be? Where should I start on testing this? I don't know if it is the amp or the sub. Thank you in advance for any help.

Okay, thanks for that. I disconnected the sub from the amp, and that solved the random shut downs. Now I just need to figure out what is up with the sub, or sub channel of the amp. I will disassemble the sub box and check all the wiring for pinches or shorts. Is there anything else I should do? Would a blown sub cause problems like what I experienced? Sorry if these questions are stupid, I have installed a lot of systems, just never had to troubleshoot one.

yes, a blown sub will do exactly what you are experiencing.