Well I don't know if you have already fixed your problem as seeing it was posted in Sept, but I just had the same exact problem with my 83 380 sel, the window would not move but was working perfectly before. check the switch it is quite easy. When you remove it , also remove the affected button slowly, a lot of gunk had accumulated and thus when I pressed the switch the contacts where blocked by the gunk, so the window didn't move. clean up with some CRC and window was perfect, I would say 96 % that that is your problem.
**A few Hondas etc... etc... Not Worth Mentioning**
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