1990 corsica

high beam works--low beam does not--bulbs ok--any ideas

First thing I would suspect is the dimmer switch. You can sometimes put presure on lever to make it work to confirm problem.

I know this is an old post but just in case...the dimmer switches work loose over time and sometimes need to be adjusted and tightened again, or it could be bad. Down under dash near floor. Has a rod running through steering shaft from handle...