You shouldn't have to take a lot apart to check the wires in the rubber door boot. All you need to do is remove the inner door panel and un-screw the door speaker, nothing more. You can use the speaker hole as a larger access port for your hand to grab and check the wires by pulling on them to see if one is broken. A broken wire will pull back into the door from the rubber boot where it broke apart. To remove and check the wire ends in the rubber boot itself, just push the rubber boot (Inner door part) end from inside the door out into the door jam area, and then you can push the body end of the boot inside the body of the vehicle into the hole at that end of it as far as it will go into the body hole. This will give you a little extra room to check the wires in the boot area and to repair them at that end. It is a PITA getting your fingers into the door jam area and splicing into a broken wire end there. That was the hardest part of the job. I just repaired a broken wire in my drivers door boot last week for a power wire to my passenger side front window.
BTW, you are talking to the right person for help "BigRondo"!