Dred,
There are hidden internal splices in the factory harness. Cleaning or replacing only the ends does not necessarily solve the problem. There can be heavy corrosion still hiding. There are some pictures at the bottom of my JS Restorations thread on page 2 at the bottom that shows before and after with those splices. Take a meter and check the impedance on the lines from the master switch socket to the ends for the passenger motors and see what you read.
https://board.moparts.org/ubbthreads/show...part=1&vc=1Jim
