1996 Nissan Maxima blower only turns on on #4

Hi, my 96 nissan making cool's fine, but the a/c blower only runs on #4 speed which is full blast. On #'rs 1, 2, &3, the compressor come's on but the blower dont do any thing unless you turn the control to # 4.I have already changed the a/c control's on the dash board but nothing same to change. Any idea's, please help. Thank you