If you can get one switch and window motor to correctly function that will be a help for your troubleshooting.
that will confirm you have one correctly wired switch and one operating motor.
(getting the wires correctly connected on those window switches is still a problem for me after 20 years)
you can then use the good switch to control the bad motor and see what happens
you can use the unproven switch with the good motor to confirm if you have two good switches
if your 12 V testing is just with a motor sitting on a bench, that is a different world than with the motor connected to the gear drive and raising the window
thanks for the additional information.
if you haven’t already you should study the wiring diagrams at panteraplace.com
Larry
