I got one for you guys few months ago my blower motor in my 1996 k1500 Z-71 it started making the most god awful racket then locked up well I replaced the motor doesn't work replaced the relay doesn't work replaced the resistor and surprise surprise still no blower motor functions I checked every damn fuse in the truck nothing is blown so do my heater does still work fortunately just takes a bit do I need to replace the control unit on the dash? Knowing that after all the bs that won't fix anything as much as I love gm trucks they always develop some of bs electrical issues eventually.

 

Nothing on any speed?
check the connectors. seized motors will often fry them out.

 

It's the darkest thing nothing no blower speed nothing from the blower connectors good no burnt or shorted wires I don't think the control is bad temp dial and vent selection still seems to work the parts are new not remanned that I know of so either I got a bad part right out of the box which isn't uncommon or I have another issue somewhere I guess I need to start chasing wires again.

 

have you tried putting 12V directly on the motor to make sure it works?
You'll need an electrical schematic to troubleshoot further.

 

Nope I suppose should have done have done that to start with . I guess we will see what happens.