flip the dimmer switch to high beam, and the dash HB lite comes ...

I have a 2012 chevy 2500hd silverado,6.6diesel4x4 longbox I have DRL and either lowbeam or highbeam headlights depending on which way i turn the relay around . If i have low beams, i can flip the dimmer switch to high beam, and the dash HB lite comes on but the HBs do not come on.