Why is my A/C condenser fan motor wiring backwards, and how can I fix it?
Yes, the concave shape should always curve in the direction of the air flow...

(Click to enlarge.)




Switching the L1 and L2 wires wouldn't change the motor's direction and the colors are a bit arbitrary since this is a 220V circuit.  Verify that it is 220V and that neither wire is the neutral, then mark the white wire with black electrician's tape to signal that it is "hot" too.

It's a common thing to switch the polarity of the start windings relative to the run windings to change an AC motor's direction.  These are usually yellow and orange wires, and the previous installer may have switched these.  If you can't tell that this kind of switch was done, don't worry about it and set the new motor's jumper to get it spinning in the right direction.

But, if you aren't certain or comfortable with the situation, have an electrician look it over.