I know you guys like a challenge with an ambiguous diagnosis, so how about this one. My sub worked last year, now it doesn't. The Alpine Mono amp that goes to it lights up. I think that means that remote lead and power/ground are out. I have freshened the tips of the speaker wire at the box terminal and speaker, but not the amp. I have a WS420 in line as well. I have swapped RCAs, and that did not help. So I am thinking run a speaker wire straight to the box and check that? Otherwise, it is something internal in the amp? Thoughts?

Thanks in advance!