I have a 2006 crew cab with the factory head unit and factory speakers. My problem is that my speakers are starting to fail one at a time. It started with the front passenger woofer and moved to the front driverside woofer and now it has moved to the rear passenger speaker. The tweeters still work and the front driverside woofer will work when it is really hot outside. Could it be the radio or the speakers? Any help would be greatly appreciated.