I tried doing a search but couldn't find anything so...

I noticed when i'm in park and push my window button, the dash light dims and the revs drop a bit. Maybe i'm just being paranoid, but how much power does it take to roll down a window? Normal? not normal? signs of something bad to come? Thanks!

 

Pretty much every car I've ever owned with any sort of mileage (60k+) would dim a little (but not much) when load was put on it at idle. My TL with 59k does it. However, if it seems extreme, it may be a sign of the charging system (alternator) going bad.