what to do when low beam is out want come on on 2006 Buick Rainier

automatic not working and turn on switch do not turn on low beam

Asked by for the 2006 Buick Rainier
It could be anything, from fuse, wireharness, headlight switch, even BCM (Body Control Module) since many accessories are control also by BCM.
1 more answer
In fuse box under the hood there r two black plugin modules one for low beams and one for high beams.My suv had the same problem.You can switch modules and see if low beams come on.module cost about 35 dollars at dealer.