Headlight go out when on low beam

A couple of years ago mice got into this vehicle's heater box. The steering wheel and dashboard was taken out to get proper access to the heater to clean up. Now a year later, the headlights will go out when on low beam. The high beam, dash lights, tail lights parking lights, and daytime running lights (Canada) always work normally. You can flick back and forth from the high to low or turn the lights on and off as many times as you want and they rarely come back on. The only thing that seems to bring them back on is if I flick to the headlight flash position for a moment.
Need help!