C10 77 BLOWER SWITCH ERROR.

[Dusty]

So I'm new, I got a new old truck.
I got the manuals.
what's this?  The blower won't shut off?
I go to the manual & it is supposed to.
I read the wiring diagram & the battery wire goes to the battery terminal on the blower switch & then goes to the slow speed on the blower resister. The slow terminal on the switch (51) isn't even on the diagram.
I pondered over this for days & the discovered I read the switch function under the wrong model in the manual.  I guess my heater motor has 93,000 miles on it too. 

[bd]

LOL!  I think GM does that to help keep the heater/AC housings dry so mildew doesn't form....

[ehjorten]

The fan will not stop when you shut it off.  It will continue to spin slowly.  That is the way it is designed to be.

[Captkaos]

It is part of the Crossflow ventilation.