info:
1990 ls400
ALL power windows work on their own switch

problem:
master (driver) window switch rolls all windows down and up fine
EXCEPT for passenger REAR window.
the master driver window switch will roll the passenger REAR window down BUT not up.

ive searched
and best thing ive came up with was from the GS forums where they say go to each door and roll down the window all the way then roll it up completely

but ive tried that, NO luck at all.

 

a master window switch can get a dirty contact internally, and can be taken apart and cleaned, but I would only do this if you are good at small meticulous things - like the kind of guy who can replace a screen in a smartphone, for example.

 

well i did switch the master switch to another same problem persists, rear passenger rolls down but doesnt go up.

would u think it could be the rear passenger switch itself?

when i see them at the junkyards again ill try and get more master switches.

 

was it verified in another car that the other master switch worked fine?

you need a buddy with 90-92 LS400 that will let you trade master switches with him, as a test

 

No I don't have anyone to borrow from
I assume 93-94 master switch won't work?? On the 90-92

Over here in Washington it's rare to find a old version ls400