blower motor resistor

hi im new here and i have a problem with my a/c speed control.my fan only worked on high so i bought a new resistor installed it and it worked for about a day.my blower motor would squeak somtimes so i bought a new oneand installed it along with a new resistor ond it works but when i turn on the a/c on any speed other then high the resistor gets hot and starts to smoke so i keep it off i ca;lled the dealer and they said i may have a short inthe system. any ideas out there on what it could be, i even replaced the control panel.please help im really trying to avoid the dealer and the high prices they charge.thank in advance.

btw it a 96 tahoe

Test/check the wire going from the resistor pack to the blower motor relay. If you have a short I would suspect that wire to cause the over heating resistor as when you select high that wire is bypassed.