a/c problems

my a/c only works on high so i replaced my blower motor resistorand it works on all speeds but it started getting hot and started smoking.i have since replaced the blower motor ,the control panel,and installed a new resistor with the same outcome,smoke!any ideas out therei could really use the help.thanks in advance.
btw its a 96 tahoe 2dr/vortec.

Have you checked your blower motor relay? Just a guess