Headlights on high
Are both the high beam and low beam headlights on when you put them in high beam mode? On my car it appears that either one or the other are on in high or low modes, but not both when I put the lights into high beam mode.
No, they do not both come on at the same time. BUT there is a cheap and simple modification you can do (I did it on mine). It's called quad beam headlights mod for Trailblazer/Envoy. You'll see a few places that show you how to do it.