Dryer does not heat, some cycles work

The timer on my dryer works on one of the cycles, but not the other three. My dryer runs but does not heat up. Any ideas?

my dryer isn’t heated, one blue wire is loose, I cann’t find where it connect to , the blue wire is close to ignitor kit, dryer’s model no. is lgr2614bw2, whirlpool. please help me, i am desperate.