I have never replaced anything with the motors... but reading enough posts about that exact thing happening, I think I know what it is.
One the one that is backwards, there is a magnet of something that need to beinstalled backwards or upside down or something like that... I'll try to find the posts..
ok I found a quote that seems to mirrow what everyone was saying...
in this thread: https://www.fiero.nl/forum/Forum2/HTML/025526.html
Rodrv6-
"I've had the same problem--Take the L/H [or R/H] motor out, open up the housing and rotate the magnet 180 degrees around the motor shaft. Don't pull the magnet off of the shaft, just rotate it and put everything back together. It should work now."
[This message has been edited by Tweek (edited 11-06-2002).]