Hey guys... just put my lights back in, for a few minutes the driver side headlamp worked fine, now only the high beam works. I switched with new bulbs and still the same thing... only highbeam. Passenger side works fine. What could cause this?

89 4Runner
3" BL, M/T locks, 33"bfg mt, bilstein, Kayline, tubebumper, toyotafiberglass panels
TBI: Elocker,3.4 w/ORS,b+b,S2Sstg2cams,arias pistons,P+P intake,TRDs/c,URDpullies+7th,downey headers,MAPECU2,WEGO WB, SupraMAF,walboro255,stg4clutch, EPaOo2 sim