I worked this past weekend. Drove to the track and parked my car on friday afternoon. I went to leave tonight and when I would turn up volume to my normal listening level the red light would come on and my sub would not work. When I parked my car on friday everything was working correctly. Any thoughts why this would happen? We did get some pretty hard rains but I have had no issues with this previously. I have been running this set up since january.  I have not had the chance to check voltages yet but any direction to why the sudden change. My current battery is just the standard car battery I purchased from sears in december. Just confused.

If the amp is going into protect it will either be a voltage problem, or possibly the subwoofers are blown/shorting out.

If the amp is going into protect it will either be a voltage problem, or possibly the subwoofers are blown/shorting out.

The sub still works at low volume. Could it still be blown?

Just have to start by process of elimination.  Start simple.  Check cables make sure everything is still tight & secure, including ground cable.  Check voltage under load.  Move on from there to the subwoofer.  Check impedance & continuity @ different excursion levels.....i.e. push & hold the cone inward & outward.