Re: Pickup Installation Question
If by install the wrong way you mean physically rotate the pu by 180 degrees then as jaden says you won't notice much difference. This is because when you look at the pu from above the windings still go the same way, (clockwise or anti-clockwise depending on the coil). The only difference you'll hear is because now different coils are nearest the neck or bridge and if the two coils are not identical, say one has slug pole pieces and the other screws, that may make a difference.
If you mean install the wrong way electrically, then that will make a difference but only when combined with another pickup, it'll give the combination a thin brittle sound.