high beam lights still work. dimmer switch may be bad
head light low beam stopped working. manual override did not work. bulbs o.k. on 2002 GMC Yukon Denali
AGREE MULTIFUNCTION SWITCH ISSUE
1 more answer , 1 more comment
check to see if you are getting power at the plug at the headlight if there is no power then you probably need a multifuction switch
Can I replace this part myself. I am not that mechanically inclined.