I had my air conditioning drain plug up and cause condensation to
build up in my heater fan motor housing. The moisture caused the fan
to no longer run in the lower speeds. It will only run in the #4 High
position. Positions 1,2 and 3 are dead. I went down to the blower
motor and tested for voltage and only received voltage when the switch
was in the #4 position. I then went to the switch and it tests fine
per the manual test procedure. My manual doesn't show much more on
the electrical side of the heater. Is the something in between that
could cause this? Is there a unit or resistor that reduces the
voltage for these other positions prior to the motor? Any help would
be appreciated.

jcoyne97222 wrote:
Bad resistor pack. It's in the air plenum behind the glove box.