What could still cause the thumping from blower fan on 92 silverado the recirc buttom did not work its still elec could this be from the ac not working because of the ac comp box in the dash what next?
The thumping from the blower is most likely something in the
blower cage. something probably got sucked out of the glove box.
the recirc button opens the max air door and could be the button or
the motor on the door itself. taking the glove box out will be the
easiest way to remove the blower although they are tucked in very
tight and it may also be necessary to remove the bottom bolt for
the dash to make enough room to get it out all the way.