Check the wiring going to the headlight cover motors and check fuse and any relays and the grounds especially I'd be changing the grounds on it and using a light test probe to trace the circuit but it could be that the motors need replacing and you'll need to buy some new ones.
Keep in mind that on any vehicle that age it's bound to have rusty or corroded connections and faulty wiring too , plus the most common vehicle electrical problems are all related to bad grounds and connections.
Hope that helps and best of luck.Happy Holidays