Left side low beam

09 western star 4900 ex Left side low beam not working it works when I put on the high beams but no low beam the right side is all good and everything else works fine, fuses look good I will test them tomorrow to make sure they have power .I pulled apart the connection under the fender no corrosion checked there for power only power on high beam, its acting like a broken wire but wiring all looks good down as far as the frame where it takes off towards the fire wall. Any suggestions .