I have Ford 2000 Expedition Eddie Bauer Edition with the Mach Audio System and my subwoofer just went out and stopped while I was driving and listening a few days ago.
How can you tell or troubleshoot whether it's the power amp or the subwoofer that's blown?

Any help in this matter would be greatly apprecitiated!

 

Just found that my subwoofer is blown. Looking to to replace the sub.