If car has factory A/C, on the passenger floorboard you will find the blower motor (behind the glove box). If glovebox was removed, it will look something like this (this is the ’80-89 version, the ’76-79 version will look similar).
There is no mention of year car in this thread.
If your car is not a factory A/C car, then the above data will not be correct.
Under the evaporator case there will be a pair of thick wires, one black and other green. The green wire will lead to the blower resistor. The black wire will lead straight to ground via a small screw.
The ground connection doesn’t give much trouble – but if a repair was recently performed in the area, it is often left detached (unscrewed).
The blower resistor is not a part that fails that often.
The possible trouble areas are:
Melted fusible link (underhood, close to brake booster).
Blown fuse
Ignition switch
A/C controller switch
Blower speed switch (attached to A/C control head)
Blower resistor
Blower motor
Poor blower ground
And lastly, a break in wiring harness between any of the above items.
BudW