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Blower Motor Inoperative (SRT10)

BLOWER MOTOR INOPERATIVE (SRT10)

Blower Motor Inoperative (SRT10):





POSSIBLE CAUSES
- Faults present in the front control module (FCM)
- (C7) Blower motor feed circuit shorted to (Z1) ground circuit
- (A970) Fused B(+) circuit shorted to (Z1) ground circuit
- (C7) Blower motor feed circuit shorted to ground
- (A970) Fused B(+) circuit shorted to ground
- (Z1) Ground circuit open
- (A970) Fused B(+) circuit open
- (F102) Fused ignition switch output (run) circuit open
- (C7) Blower motor feed circuit open
- (C70) Blower motor high driver circuit open
- (Z134) Ground circuit open
- IPM fuse #4 open
- Blower motor relay
- Blower motor
- A/C heater control

Diagnostic Test

1. CHECK FOR ACTIVE DTCs IN THE FRONT CONTROL MODULE (FCM)
Turn the ignition on.
With the DRBIII(R), read active Front Control Module DTCs.

Q: Does the DRBIII(R) display any active DTCs?

YES: Diagnose and repair the DTC(s). Perform BODY VERIFICATION TEST - VER 1. Body Verification Test
NO: Go To 2

2. CHECK THE FUSE




Turn the ignition off.
Remove and inspect IPM Fuse #4.

Q: Is the fuse open?

YES: Replace IPM Fuse #4 and Go To 3.
NO: Reinstall IPM Fuse #4 and Go To 7.

3. CHECK BLOWER MOTOR OPERATION
Turn the ignition on.
Turn the blower on and operate it in all speeds and modes.

Q: Does the blower motor operate properly without blowing the fuse?

YES: Check the (C7) Blower Motor Feed circuit and the (A970) Fused B(+) circuit for an intermittent short to ground. Repair as necessary. Perform BODY VERIFICATION TEST - VER 1. Body Verification Test
NO: Go To 4

4. CHECK THE (C7) BLOWER MOTOR FEED CIRCUIT & THE (A970) FUSED B(+) CIRCUIT FOR A SHORT TO THE (Z1) GROUND CIRCUIT




Turn the ignition off.
Remove the Blower Motor Relay from the IPM.
Measure the resistance between the (Z1) Ground circuit and the (C7) Blower Motor Feed circuit in the Blower Motor Relay connector.
Measure the resistance between the (Z1) Ground circuit and the (A970) Fused B(+) in the Blower Motor Relay connector.

Q: Is the resistance below 10K ohms on either circuit?

YES: Repair all circuits with a resistance below 10k ohms for a short to the (Z1) Ground circuit and replace the fuse. Perform BODY VERIFICATION TEST - VER 1. Body Verification Test
NO: Go To 5

5. CHECK THE (C7) BLOWER MOTOR FEED CIRCUIT FOR A SHORT TO GROUND




Disconnect the Blower Motor harness connector.
Measure the resistance of the (C7) Blower Motor Feed circuit between ground and the Blower Motor harness connector.

Q: Is the resistance below 10K ohms?

YES: Repair the (C7) Blower Motor Feed circuit for a short to ground and replace the fuse. Perform BODY VERIFICATION TEST - VER 1. Body Verification Test
NO: Go To 6

6. CHECK THE (A970) FUSED B(+) CIRCUIT FOR A SHORT TO GROUND




Measure the resistance of the (A970) Fused B(+) circuit between ground and the Blower Motor Relay connector.

Q: Is the resistance below 10K ohms?

YES: Repair the (A970) Fused B(+) circuit for a short to ground and replace the fuse. Perform BODY VERIFICATION TEST - VER 1. Body Verification Test
NO: Replace the Blower Motor and fuse. Perform BODY VERIFICATION TEST - VER 1. Body Verification Test

7. CHECK BLOWER MOTOR OPERATION WITH A SUBSTITUTE RELAY INSTALLED
Install a substitute relay in place of the existing Blower Motor Relay.
Turn the ignition on.
Turn the blower on and operate it in all speeds and modes.

Q: Does the blower motor operate properly?

YES: Replace the Blower Motor Relay. Perform BODY VERIFICATION TEST - VER 1. Body Verification Test
NO: Go To 8

8. CHECK THE (Z1) GROUND CIRCUIT FOR AN OPEN




Turn the ignition off.
Remove the substitute Blower Motor Relay.
Measure the resistance between ground and the (Z1) Ground circuit in the Blower Motor Relay connector.

Q: Is the resistance below 5.0 ohms?

YES: Go To 9
NO: Repair the (Z1) Ground circuit for an open. Perform BODY VERIFICATION TEST - VER 1. Body Verification Test

9. CHECK THE (A970) FUSED B(+) CIRCUIT & THE (F102) FUSED IGNITION SWITCH OUTPUT (RUN) CIRCUIT FOR AN OPEN




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, check the (A970) Fused B(+) circuit in the Blower Motor Relay Connector.
Using a 12-volt test light connected to ground, check the (F102) Fused Ignition Switch Output (Run) circuit in the Blower Motor Relay Connector.

Q: Does the test light illuminate brightly on both circuits?

YES: Go To 10
NO: Repair the circuits that failed to illuminate the test light brightly for an open circuit. Perform BODY VERIFICATION TEST - VER 1. Body Verification Test

10. CHECK THE (C7) BLOWER MOTOR FEED CIRCUIT FOR AN OPEN




Turn the ignition off.
Install the Blower Motor Relay.
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, back probe the (C7) Blower Motor Feed circuit in the Blower Motor harness connector.

Q: Does the test light illuminate brightly?

YES: Go To 11
NO: Repair the (C7) Blower Motor Feed circuit for an open. Perform BODY VERIFICATION TEST - VER 1. Body Verification Test

11. CHECK BLOWER MOTOR OPERATION BY BYPASSING THE A/C HEATER CONTROL




Turn the ignition off.
Connect a jumper wire between ground and the (C70) Blower Motor High Driver circuit in the Blower Motor harness connector.
Turn the ignition on.

Q: Does the blower motor run at high speed?

YES: Go To 12
NO: Replace the Blower Motor. Perform BODY VERIFICATION TEST - VER 1. Body Verification Test

12. CHECK THE (C70) BLOWER MOTOR HIGH DRIVER CIRCUIT FOR AN OPEN




Turn the ignition off.
Disconnect the A/C Heater Control C2 harness connector.
Disconnect the Blower Motor harness connector.
Measure the resistance of the (C70) Blower Motor High Driver circuit between the A/C Heater Control C2 harness connector and the Blower Motor harness connector.

Q: Is the resistance below 5.0 ohms?

YES: Go To 13
NO: Repair the (C70) Blower Motor High Driver circuit for an open. Perform BODY VERIFICATION TEST - VER 1. Body Verification Test

13. CHECK THE (Z134) GROUND CIRCUIT FOR AN OPEN




Measure the resistance of the (Z134) Ground circuit between ground and the A/C Heater Control C2 harness connector.

Q: Is the resistance below 5.0 ohms?

YES: Replace the A/C Heater Control.
NO: Repair the (Z134) Ground circuit for an open. Perform BODY VERIFICATION TEST - VER 1. Body Verification Test
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