Why would the wires go to the wrong places? About the most you can do is fit the big round connector incorrectly. The turn signals won't work properly if you get this connector wrong (don't ask how I know). Very obvious. If you have a problem with lighting, check the bulbs and the dimmer.

I can help you go wire by wire but that will take a while and I'm 99.9% sure you'll find everything in order. What kind of hack owned the car before you that makes you think the wires were rearranged?

Sixto
95 S420
87 300SDL