Most likely the headlight relay. The relay switches between high and low beams. As low beams are used more, they are the relay contacts more prone to corrosion
Check all fuses and check for burn out headlights, high and low beams
I would first check all fuses. My 2002 uses a weird configuration and requires several fuses to work all of the lights properly.
The headlights are on two different fuses. The high beams are on one fuse and the low beams are on another fuse. The fuse for the low beams may need to be changed.
Check the fuses.
The headlights are on two different fuses. The high beams are on one fuse and the low beams are on another fuse. The fuse for the low beams may need to be changed.
check the fuses - there is no fuse for the headlights.
A short in the low beam circuit.
check the fuses
If the headlights are not working correctly on a 1990 Corvette, the fuses or lights could be going out. Replace the old fuses and check that all wires connected to the lights are functioning correctly.
If some of the lights work on the car and some are just clicking, there may be a short in some of the electrical wiring. There may also be a problem with the electrical relays, fuses, or actual bulbs.
Have you checked the fuses?
Check bulbs Check relay Check dimmer switch If it has daytime running lights (DLR) then try removing the DLR module. I had one where high beams worked when pulling back, but high beams would not work when pushing forward. The regular headlights would not turn on at all. The interior lights and instrument lights all worked fine. The fix was to replace the multifunction switch (turn signal lever).