There were times when it would cut in and out when I first got the Jeep (00 Cherokee Sport), but it always eventually started working.

I installed an aftermarket head unit (sony xplod), had some problems with the wiring harness adapter being labeled wrong so ONLY the passenger front door speaker was working.

Well, I looked up the wiring diagram for the Cherokee and compared it to the wiring diagram for the xplod and figured out what was wrong, and corrected the wiring.

Now the rest of the speakers are working, and sounding WAY better than I thought they could (amazing what a little power can do for a speaker), but the driver's door speaker is completely dead. I took the door panel off and checked the connector... it's on there.

Are there any KNOWN reasons why door speakers cut out completely?

 

Yes. The wires tend to get shortened or just wear when the door is opened and closed. Pull your kick panel and check the wires where they go into the door.

 

I ran a new wire from my harness to the door speaker, and still it didn't work. On further investigation, the plug on the speaker looked good and was connected well but it was my problem. I cut it off and soldered the wires directly to the speaker and Bob's your uncle it works!

 

this should be in OEM tech not advanced