I replaced alternator and car started but now lights inside flashing when door open?

I suspect a bad ground wire from the alternator....be sure that the unit IS grounded properly~

a wirebrush....follow the 1/0 black battery cable to the spot where it attaches at the chassis/ground....take the bolt out of there and with a pliers and wirebrush clean all the corrosion off of that lug and the spot to which it bolts....this clean and solid chassis ground will "wake up the radio too~

All I can think of is that your current problems caused the alternator to fail, not that the replaced alternator caused your problems.. I think you might have a problem inside your dashboard. Bring the car into the dealer. They can read the codes and hopefully find the problem. Oh yeah,if you store coins anywhere on the dashboard, have any gone missing?

"sunshine" brand alternators.....cleaned up wreckers and put in a box~