This is 3 days after installed. Anyone know what would cause it? The gain and frequency on the amp was set at factory recommendations. Volume about 3/4 up. Just went out and caused the fuse in the amp to pop

 

Nice. Thats an electrolytic capacitior that popped. It that a piece of "active" electronics or a passive crossover? Over voltage is a common casue of electrolytic failure, NOT to say your battery voltage was at fault (could have been another failure of another component in the crossover that subsequently OV'd the capacitor). Capacitors, like the one pictured, are polarity specific and installing them backwards (rare) is another cause of failure; can fail weeks later. Root casue of your failure could be many dozen things.....including a manufacturing defect which is most likely, IMO.

 

This is what I am thinking. Polarity was correct, and volume wasn't pushing it any harder than the setting recommended by supplier to tune. I am waiting for them to open on Tues and find out a little more. Thanks