It is much more likely that the problem is not in the rear door itself. Instead,
the very first place to look is in the driver's door hinge area. You will see a
rubber accordion tube that contains all the wires to operate the windows,
sunroof and mirrors. Over time the flexing breaks the wires in there and causes
all sorts of problems.
Try to use a flexible wire like marine grade with more strands to avoid cracking
in the future. Open it up, find broken wires, solder and heat shrink. There
are a lot of wires in there so look carefully.
Motorsforum.com is a website by car enthusiasts for car enthusiasts. It is not affiliated with any of the car or spare part manufacturers or car dealers discussed here.
All logos and trade names are the property of their respective owners.