"I couldn't find a broken wire visibly, and really there was no need to do so. The speaker wasn't working and there are only 2 wires connecting it. Simply re-run the 2 wires as this is a notorious issue on the XJ. The first step is to locate the wires that are affected and note their color. If you are only replacing a few of the wires, there really is no need to remove the old wire. Sometimes (as was the case for me here) the old wire is stuck or brittle enough that it continues to break if you try to pull it through. The easiest was to run the new wire was to use something to fish the wire. In my case an old metal coat hanger was available. Be sure to bend the end back to make a blunt point. I doubled it over and crimped it tightly together with pliers. Next, it seemed logically to me to push from the inside (cabin area) out due to the door boot design of the harness. Also note that there was a wire-tie on the inside boot to keep it tight. I cut this off while running the new wires and you can replace it after. Push the coat hanger down the center of the wire bundle and feed it through the harness into the door frame. Now, create an eye by doubling the other end of the coat hanger over with pliers. Loop the new wire around (think inter-locking index fingers of opposite hands). Try to get everthing as small as possible to help pulling through. You want to minimize bulk. Also use electrical tape to cover this joint of wire and coat hanger. One more thing that will help is to use a soapy water solution. Just a small amount will work wonders. Caveat emptor as you may be working on power wires that have cracked insulation, but know that auto plants use similar techniques on the assembly line when running some of the harnesses. Now you should be able to pull the hanger through and the wire will follow. use butt-splices to repair the suspect wires and you should be all set.

Notes:
-You may need to perform the procedure more than once, depending on the number of wires you are replacing. In my case, I pulled 4 in one shot without issue.
-If the inter-door boot or the cabin boot become dislodged, you can easily re-seat them in the sheet metal. The soapy water solution will help here, too.
-Be sure to use appropriate grade wire for the repair... and definitely use something more flexible than the OE design and its poorly engineered (was it even tested) fatigue life in this area.

Good luck!"