The rear windows not working are probably a result of broken wires in the rubber elbow between the door and body pillar. Apparently typical for this vintage, I've had to do the fix for my hatch & left rear door. It isn't hard, just diddly and time consuming (set aside a full afternoon). You need to carefully pull the elbow and find the break (should be pretty obvious if it has parted, but not if the insulation is still intact). I found it was helpful to remove the inner door skin and solder the splice on either end of the elbow, I used stranded zip cord (12 gauge I think).

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1999 E320 (gave to daughter) 250K
1994 F150 (may be the end of its road) 240K
1989 560 SL (Reassembly after paint job) 160K
1986 560 SL (deceased., gave it's life protecting my wife)
1988 300 TE (departed)
1994 945T (still running strong with an upgraded cam) 349K
1986 242Ti (deceased)
1968 GT500KR (under restoration)