Chrysler Town, Dodge Caravan. Manual — part 836

TEST

ACTION

APPLICABILITY

3

Replace IPM Fuse #12.
Turn the ignition on.
Turn the Power switch on the A/C - Heater Control Module on.
Turn the rear blower on and operate it in all speeds and modes.
Does the blower motor operate properly without blowing the fuse?

All

Yes

→ Check the Fused Rear Blower Motor Relay Output circuit for an

intermittent short to ground. Repair as necessary.
Perform BODY VERIFICATION TEST - VER 1.

No

→ Go To 4

4

Turn the ignition off.
Disconnect the Rear Blower Motor 2-pin harness connector.
Measure the resistance between ground and the Fused Rear Blower Motor Relay
Output circuit.
Is the resistance below 10K ohms?

All

Yes

→ Repair the Fused Rear Blower Motor Relay Output circuit for a

short to ground. Replace IPM Fuse #12.
Perform BODY VERIFICATION TEST - VER 1.

No

→ Replace the Rear Blower Motor in accordance with the Service

Information. Replace IPM Fuse #12
Perform BODY VERIFICATION TEST - VER 1.

5

Ensure IPM Fuse #12 is installed.
Disconnect the Rear Blower Front Control Switch harness connector.
Turn the ignition on.
Turn the Power switch on the A/C - Heater Control Module on.
NOTE: The test light must illuminate brightly. Compare the brightness to
that of a direct connection to the battery.
Using a 12-volt test light connected to ground, back probe the Rear Blower Motor
High circuit in the Rear Blower Front Control Switch harness connector.
Does the test light illuminate brightly?

All

Yes

→ Go To 6

No

→ Go To 7

6

Turn the ignition off.
Disconnect the Rear Blower Front Control Switch harness connector.
Measure the resistance of the Ground circuit between the Rear Blower Front Control
Switch harness connector and ground.
Is the resistance below 5.0 ohms?

All

Yes

→ Replace the A/C - Heater Control Module in accordance with the

Service Information.
Perform BODY VERIFICATION TEST - VER 1.

No

→ Repair the Ground circuit for an open.

Perform BODY VERIFICATION TEST - VER 1.

580

HEATING & A/C

*REAR BLOWER MOTOR INOPERATIVE - MTC —

Continued

TEST

ACTION

APPLICABILITY

7

Turn the ignition on.
Turn the Power switch on the A/C - Heater Control Module on.
NOTE: The test light must illuminate brightly. Compare the brightness to
that of a direct connection to the battery.
Using a 12-volt test light connected to ground, back probe the Fused Rear Blower
Motor Relay Output circuit in the Rear Blower Motor 2-pin harness connector.
Does the test light illuminate brightly?

All

Yes

→ Go To 8

No

→ Go To 11

8

Turn the Power switch on the A/C - Heater Control Module off.
Turn the ignition off.
Using a jumper wire connected to ground, back probe the DB/OR wire in the Rear
Blower Motor 2-pin harness connector.
Turn the ignition on.
Turn the Power switch on the A/C - Heater Control Module on.
Does the blower motor run at high speed?

All

Yes

→ Go To 9

No

→ Replace the Rear Blower Motor in accordance with the Service

Information.
Perform BODY VERIFICATION TEST - VER 1.

9

Turn the ignition off.
Disconnect the Rear Blower Motor 2-pin harness connector.
Disconnect the Rear Blower Motor Resistor Block harness connector.
Measure the resistance of the DB/OR wire between the Rear Blower Motor 2-pin
harness connector and the Rear Blower Motor Resistor Block harness connector.
Is the resistance below 5 ohms?

All

Yes

→ Go To 10

No

→ Repair the DB/OR wire between the Rear Blower Motor 2-pin

harness connector and the Rear Blower Motor Resistor Block
harness connector for an open.
Perform BODY VERIFICATION TEST - VER 1.

10

Turn the ignition off.
Disconnect the Rear Blower Motor Resistor Block harness connector.
Disconnect the Rear Blower Front Control Switch harness connector.
Measure the resistance of the Rear Blower Motor High circuit between the Rear
Blower Motor Resistor Block harness connector and the Rear Blower Front Control
Switch harness connector.
Is the resistance below 5 ohms?

All

Yes

→ Replace the Rear Blower Motor Resistor Block in accordance with

the Service Information.
Perform BODY VERIFICATION TEST - VER 1.

No

→ Repair the Rear Blower Motor High circuit for an open.

Perform BODY VERIFICATION TEST - VER 1.

581

HEATING & A/C

*REAR BLOWER MOTOR INOPERATIVE - MTC —

Continued

TEST

ACTION

APPLICABILITY

11

Turn the ignition off.
Remove the Rear Blower Motor Relay from the IPM.
NOTE: The test light must illuminate brightly. Compare the brightness to
that of a direct connection to the battery.
Using a 12-volt test light connected to ground, probe cavity 30 of the Rear Blower
Motor Relay connector.
Does the test light illuminate brightly?

All

Yes

→ Go To 12

No

→ Replace the IPM in accordance with the Service Information.

Perform BODY VERIFICATION TEST - VER 1.

12

Turn the ignition off.
Remove the Rear Blower Motor Relay from the IPM.
Remove IPM Fuse #12.
Measure the resistance between cavity 87 of the Rear Blower Motor Relay connector
and IPM Fuse #12 (power input cavity).
Is the resistance below 5 ohms?

All

Yes

→ Go To 13

No

→ Replace the IPM in accordance with the Service Information.

Perform BODY VERIFICATION TEST - VER 1.

13

Turn the ignition off.
Make sure that the Rear Blower Motor Relay is installed.
Remove IPM Fuse #12.
Turn the ignition on.
NOTE: The test light must illuminate brightly. Compare the brightness to
that of a direct connection to the battery.
Using a 12-volt test light connected to ground, probe IPM Fuse #12 (power input
cavity).
Does the test light illuminate brightly?

All

Yes

→ Go To 14

No

→ Replace the Rear Blower Motor Relay in accordance with the

Service Information.
Perform BODY VERIFICATION TEST - VER 1.

14

Turn the ignition off.
Remove IPM Fuse #12.
Disconnect the IPM C8 harness connector.
Measure the resistance between IPM Fuse #12 (power output cavity) and cavity 7 of
the IPM C8 connector (IPM side).
Is the resistance below 5 ohms?

All

Yes

→ Repair the Fused Rear Blower Motor Relay Output circuit for an

open.
Perform BODY VERIFICATION TEST - VER 1.

No

→ Replace the IPM in accordance with the Service Information.

Perform BODY VERIFICATION TEST - VER 1.

582

HEATING & A/C

*REAR BLOWER MOTOR INOPERATIVE - MTC —

Continued

Symptom:

*REAR BLOWER MOTOR SPEEDS INCORRECT - MTC

POSSIBLE CAUSES

REAR BLOWER REAR CONTROL SWITCH

REAR BLOWER MOTOR DRIVER CIRCUIT(S) SHORTED TO GROUND

A/C - HEATER CONTROL MODULE

REAR BLOWER REAR CONTROL SWITCH

REAR BLOWER MOTOR DRIVER CIRCUIT(S) SHORTED TO VOLTAGE

REAR BLOWER MOTOR FRONT CONTROL FEED CIRCUIT SHORTED TO VOLTAGE

REAR BLOWER DRIVER CKT(S) SHORTED TO REAR BLOWER FRONT CONTROL FEED CKT

REAR BLOWER MOTOR DRIVER CIRCUITS SHORTED TOGETHER

A/C - HEATER CONTROL MODULE

REAR BLOWER MOTOR DRIVER CIRCUIT(S) OPEN

REAR BLOWER MOTOR RESISTOR BLOCK

TEST

ACTION

APPLICABILITY

1

Turn the Rear Blower switch on the A/C - Heater Control Module off.
Turn the ignition on.
Turn the Power switch on the A/C - Heater Control Module on.
Does the rear blower run?

All

Yes

→ Go To 2

No

→ Go To 4

2

Turn the Rear Blower switch on the A/C - Heater Control Module off.
Turn the Power switch on the A/C - Heater Control Module off.
Turn the ignition off.
Disconnect the Rear Blower Rear Control Switch C1 harness connector.
Turn the ignition on.
Turn the Power switch on the A/C - Heater Control Module on.
Does the rear blower run?

All

Yes

→ Go To 3

No

→ Replace the Rear Blower Rear Control Switch in accordance with

the Service Information.
Perform BODY VERIFICATION TEST - VER 1.

583

HEATING & A/C