Why won't my Chrysler blower motor won't turn off?

Answer 1

You must have the automatic controls for you HVAC system. The blower power module is what has failed and needs to be replaced.

This view is from the firewall side of the HVAC case but you can see the module location on the bottom of the case [http://www.justanswer.com/view_image.aspx?href=http://ww2.justanswer.com/uploads/Joecamel90/2009-10-05_101545_blo.gif] If you have the AC Auto controls, you do not have a resistor, you have a power module. Here are instructions covering both the resistor and the module from the service manual:


BLOWER MOTOR RESISTOR
DESCRIPTION
A blower motor resistor is used on this model when
it is equipped with the manual heater-A/C control
(Fig. 9). Models equipped with the optional Auto-matic
Temperature Control (ATC) use a blower power
module, instead of the blower motor resistor. The
blower motor resistor is installed in a mounting hole
in the heater/AC housing, directly behind the glove
box opening of the instrument panel. The resistor
consists of a molded plastic mounting plate with two
integral connector receptacles. Concealed behind the
mounting plate within the heater/AC housing are
four coiled resistor wires contained within a protec-tive
stamped steel cage. The resistor mounting plate
is secured with two screws to the heater/AC housing
and is accessed for service by rolling down the glove
box from the instrument panel.
The blower motor resistor wires will get hot when
in use. Do not touch the resistor wires or the protec-tive
cage if the blower motor has been running. The
blower motor resistor cannot be adjusted or repaired
and, if faulty or damaged, it must be replaced.
OPERATION
The blower motor resistor is connected to the vehi-cle
electrical system through a dedicated take out
and connector of the instrument panel wire harness.
A second connector receptacle receives the pigtail
wire connector from the blower motor. The blower
motor resistor has multiple resistor wires, each of
which will reduce the current flow through the
blower motor to change the blower motor speed. The
blower motor switch in the manual heater-A/C con-trol
directs the ground path for the blower motor
through the correct resistor wire to obtain the
selected speed. With the blower motor switch in the
lowest speed position, the ground path for the motor
is applied through all of the resistor wires. Each
higher speed selected with the blower motor switch
applies the blower motor ground path through fewer
of the resistor wires, increasing the blower motor
speed. When the blower motor switch is in the high-est
speed position, the blower motor resistor wires
are bypassed and the blower motor receives a direct
path to ground through the blower motor switch. The
blower motor resistor may be diagnosed using con-ventional
diagnostic tools and methods.
DIAGNOSIS AND TESTING - BLOWER MOTOR
RESISTOR
Refer to the appropriate wiring information. The
wiring information includes wiring diagrams, proper
wire and connector repair procedures, details of wire
harness routing and retention, connector pin-out
information and location views for the various wire
harness connectors, splices and grounds.
(1) Disconnect and isolate the battery negative
cable.
(2) Disconnect the instrument panel wire harness
connector for the blower motor resistor and the
blower motor pigtail wire connector from the resistor
connector receptacles.
(3) Check for continuity between each of the
blower motor switch input terminals of the blower
motor resistor and the resistor output terminal. In
each case there should be continuity. If OK, repair
the instrument panel wire harness circuits between
the blower motor switch and the blower motor resis-tor
or the blower motor pigtail wires as required. If
not OK, replace the faulty blower motor resistor.

REMOVAL
WARNING: THE BLOWER MOTOR RESISTOR MAY
GET VERY HOT DURING NORMAL OPERATION. IF
THE BLOWER MOTOR WAS TURNED ON, WAIT
FIVE MINUTES TO ALLOW THE BLOWER MOTOR
RESISTOR TO COOL BEFORE PERFORMING DIAG-NOSIS
OR SERVICE. FAILURE TO TAKE THIS PRE-CAUTION
CAN RESULT IN PERSONAL INJURY.
CAUTION: Do not operate the blower motor with the
blower motor resistor removed from the circuit.
Failure to take this precaution can result in vehicle
damage.
(1) Disconnect and isolate the battery negative
cable.
(2) Open the glove box.
(3) Flex both sides of the glove box bin inward
near the top far enough for the rubber glove box stop
bumpers to clear the sides of the glove box opening,
then roll the glove box downward.
(4) Reach through the glove box opening to access
and disconnect the instrument panel wire harness
connector for the blower motor resistor from the
resistor connector receptacle (Fig. 10).
(5) Reach through the glove box opening to access
and disconnect the blower motor pigtail wire connec-tor
from the resistor connector receptacle.
(6) Remove the two screws that secure the blower
motor resistor to the evaporator housing.
(7) Remove the blower motor resistor from the
evaporator housing.
INSTALLATION
CAUTION: Do not operate the blower motor with the
blower motor resistor removed from the circuit.
Failure to take this precaution can result in vehicle
(1) Position the blower motor resistor into the
evaporator housing.
(2) Install and tighten the two screws that secure
the blower motor resistor to the evaporator housing.
Tighten the screws to 2 N•m (17 in. lbs.).
(3) Reconnect the blower motor pigtail wire con-nector
to the blower motor resistor connector recep-tacle.
(4) Reconnect the instrument panel wire harness
connector for the blower motor resistor to the resistor
connector receptacle.
(5) Flex both sides of the glove box bin inward
near the top far enough for the rubber glove box stop
bumpers to clear the sides of the glove box opening,
then roll the glove box upward.
(6) Close and latch the glove box.
(7) Reconnect the battery negative cable.



POWER MODULE
DESCRIPTION
A blower power module is used on this model when
it is equipped with the optional Automatic Tempera-ture
Control (ATC) (Fig. 22). Models equipped with
the standard manual heater-A/C control use a blower
motor resistor, instead of the blower power module.
The blower power module is installed in a mounting
hole in the evaporator housing, directly behind the
glove box opening of the instrument panel. The mod-ule
consists of a molded plastic mounting plate with
two integral connector receptacles. Concealed behind
the mounting plate within the evaporator housing is
the power module electronic circuitry and a large
finned, heat sink. The module mounting plate is
secured with two screws to the evaporator housing
and is accessed for service by rolling down the glove
box from the instrument panel.
The power module heat sink will get hot when in
use. Do not touch the heat sink if the blower motor
has been running. The blower power module cannot
be adjusted or repaired and, if faulty or damaged, it
must be replaced.
OPERATION
The blower power module is connected to the vehi-cle
electrical system through a dedicated take out
and connector of the instrument panel wire harness.
A second connector receptacle receives the pigtail
wire connector from the blower motor. The blower
power module allows the microprocessor-based Auto-matic
Temperature Control (ATC) heater-A/C control
module to calculate and provide infinitely variable
blower motor speeds based upon either manual
blower switch input or the ATC programming using a
Pulse Width Modulated (PWM) circuit strategy. The
PWM voltage is applied to a comparator circuit
which compares the PWM signal voltage to the
blower motor feedback voltage. The resulting output
drives the power module circuitry, which adjusts the
voltage output received from the blower motor relay
to change or maintain the desired blower speed. The
blower power module is diagnosed using a DRBIIIt
scan tool. Refer to the appropriate diagnostic infor-mation.
(1) Disconnect and isolate the battery negative
cable.
(2) Open the glove box.
(3) Flex both sides of the glove box bin inward
near the top far enough for the rubber glove box stop
bumpers to clear the sides of the glove box opening,
then roll the glove box downward.
(4) Reach through the glove box opening to access
and disconnect the instrument panel wire harness
connector for the power module from the module con-nector
receptacle.
(5) Reach through the glove box opening to access
and disconnect the blower motor pigtail wire connec-tor
from the power module connector receptacle.
(6) Remove the two screws that secure the power
module to the evaporator housing.
(7) Remove the power module from the evaporator
housing.
INSTALLATION
WARNING: ON VEHICLES EQUIPPED WITH AIR-BAGS,
DISABLE THE AIRBAG SYSTEM BEFORE
ATTEMPTING ANY STEERING WHEEL, STEERING
COLUMN, OR INSTRUMENT PANEL COMPONENT
DIAGNOSIS OR SERVICE. DISCONNECT AND ISO-LATE
THE BATTERY NEGATIVE (GROUND) CABLE,
THEN WAIT TWO MINUTES FOR THE AIRBAG SYS-TEM
CAPACITOR TO DISCHARGE BEFORE PER-FORMING
FURTHER DIAGNOSIS OR SERVICE. THIS
IS THE ONLY SURE WAY TO DISABLE THE AIRBAG
SYSTEM. FAILURE TO TAKE THE PROPER PRE-CAUTIONS
COULD RESULT IN ACCIDENTAL AIR-BAG
DEPLOYMENT AND POSSIBLE PERSONAL
INJURY.
(1) Position the power module into the evaporator
housing.
(2) Install and tighten the two screws that secure
the power module to the evaporator housing. Tighten
the screws to 2 N•m (18 in. lbs.).
(3) Reconnect the blower motor pigtail wire con-nector
to the power module connector receptacle.
(4) Reconnect the instrument panel wire harness
connector for the power module to the module con-nector
receptacle.
(5) Flex both sides of the glove box bin inward
near the top far enough for the rubber glove box stop
bumpers to clear the sides of the glove box opening,
then roll the glove box upward.
(6) Close and latch the glove box.
(7) Reconnect the battery negative cable.