Just got an '01 r/t coupe with the 7 speaker infinity system. The back speakers are great and I hear sound from the tweeters on the top part of the door and the center speaker but nothing from the two woofers in the door. I checked the connectors on the amps and they seem fine. Pulled out the the factory head unit and looked it over and put it back in and no luck. Any ideas what this could be? More likely the speakers died or the amp is going out? The back speakers still kick really good.

 

Only way to tell is to check the leads for the front speakers from the HU for voltage (meaning it's good) similar to the rear speakers. Then check for voltage from the amp output. If that checks good, you'll have to pop the door panel and check the wires at the speaker. I'd wager on a bad HU myself.

Mine developed a short that killed the right side speakers shortly after it turned on. I popped in a HU from my Dad's Cherokee and everything is working fine now. I used the above method to find the voltage drop coming from the HU itself and not the amp. 7 speaker Infinity system here as well.