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For 1990-2009 cars only
Makes 🢒 Chevrolet 🢒 1999 🢒 Corvette 🢒 Body and Accessories 🢒 Data Link Communications 🢒 Blower Motor Inoperative at Any Speed

Blower Motor Inoperative at Any Speed <<C60>>

Step

Action

Value(s)

Yes

No

DEFINITION: Blower motor is inoperative at any selected speed.

1

Were you sent here from the HVAC System Check (C60)?

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Go to Step 2

Go to HVAC System Check

2
  1. Disconnect the blower motor connector.
  2. Turn the ignition switch to the ON position.
  3. Place the HVAC mode switch in the UPPER position.
  4. Turn the blower switch to the LO position.
  5. Connect a DMM between terminal A of the blower motor connector and a known good ground.
  6. Measure the available voltage at terminal A of the blower motor connector.

Is the voltage within the specified values?

10.0 -14.0V

Go to Step 3

Go to Step 10

3
  1. Connect a DMM between a good ground and terminal B of the blower motor connector.
  2. Measure CKT 150 for continuity to ground.

Is the resistance to ground less than the specified value?

0.5ohms

Go to Step 4

Go to Step 5

4

Replace the blower motor. Refer to Blower Motor and Fan Replacement .

Is the repair complete?

--

Go to HVAC System Check

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5
  1. Disconnect the blower motor control module connector C2.
  2. Connect a DMM between the blower motor control module connector C2 terminal 2 and a good ground.
  3. Measure CKT 150 for continuity to ground.

Is the resistance to ground less than the specified value?

0.5ohms

Go to Step 6

Go to Step 7

6

Locate and repair an open or a high resistance in CKT 150 (blk wire) between the blower motor connector and the blower motor control module connector C2.

Is the repair complete?

--

Go to HVAC System Check

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7
  1. Disconnect the blower motor control module connector C1.
  2. Connect a DMM between the blower motor control module connector C1 terminal E and a good ground.
  3. Measure CKT 150 for continuity to ground.

Is the resistance to ground less than the specified value?

0.5ohms

Go to Step 8

Go to Step 9

8

Replace the blower motor control module. Refer to Blower Motor Resistor Replacement .

Is the replacement complete?

--

Go to HVAC System Check

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9

Locate and repair an open or a high resistance in CKT 150 between the blower motor control module connector C1 and G202.

Is the repair complete?

--

Go to HVAC System Check

--

10
  1. Disconnect the blower motor relay.
  2. Connect a DMM between the blower motor relay connector terminal A1 and a good ground.
  3. Measure CKT 150 for continuity to ground.

Is the resistance to ground less than the specified value?

0.5ohms

Go to Step 12

Go to Step 11

11

Locate and repair an open or a high resistance in CKT 150 between the blower motor relay connector and G202.

Is the repair complete?

--

Go to HVAC System Check

--

12
  1. Connect a DMM between the blower motor relay connector terminal C2 and a good ground.
  2. Turn the ignition switch to the ON position.
  3. Measure the available voltage at the blower motor relay connector terminal C2.

Is the voltage within the specified values?

10.0 -14.0V

Go to Step 16

Go to Step 13

13

Check the HVAC MiniFuse® #18 for an open circuit.

Is the fuse open?

--

Go to Step 15

Go to Step 14

14

Locate and repair an open or a high resistance in CKT 41 between the blower motor relay connector and the instrument panel electrical center.

Is the repair complete?

--

Go to HVAC System Check

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15

Locate and repair a short to ground in CKT 41 between the blower motor relay connector and the instrument panel electrical center.

Is the repair complete?

--

Go to HVAC System Check

--

16
  1. Connect a DMM between the blower motor relay connector terminal C1 and a good ground.
  2. Measure the available voltage at the blower motor relay connector terminal C1.

Is the voltage within the specified values?

10.0 -14.0V

Go to Step 20

Go to Step 17

17

Check the BLO MOT MaxiFuse® #49 for an open circuit.

Is the fuse open?

--

Go to Step 19

Go to Step 18

18

Locate and repair an open or a high resistance in CKT 1342.

Is the repair complete?

--

Go to HVAC System Check

--

19

Locate and repair a short to ground in CKT 1342.

Is the repair complete?

--

Go to HVAC System Check

--

20
  1. Reconnect the blower motor control module connectors.
  2. Reconnect the blower motor connector.
  3. Connect a fused jumper wire between the blower motor relay connector terminal C1 and terminal A2.
  4. Turn the blower motor fan switch to the low position.

Does the blower motor operate?

--

Go to Step 21

Go to Step 22

21

Replace the blower motor relay.

Is the replacement complete?

--

Go to HVAC System Check

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22
  1. Fused jumper wire is still connected between the blower motor relay connector terminal C1 and terminal A2.
  2. Disconnect the HVAC Control Assembly connector C2.
  3. Connect a DMM between the HVAC Control Assembly connector C2 terminal B and a good ground.
  4. Measure the available voltage at the HVAC Control Assembly connector C2 terminal B.

Is the voltage within the specified values?

10.0 -14.0V

Go to Step 24

Go to Step 23

23

Locate and repair an open or a high resistance in CKT 42.

Is the repair complete?

--

Go to HVAC System Check

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24
  1. Connect the blower motor connector.
  2. Connect the blower motor control module connectors C1 and C2.
  3. Fused jumper wire is still connected between the blower motor relay connector terminal C1 and terminal A2.
  4. Connect a fused jumper wire between terminal B and terminal H of the HVAC Control Assembly connector C2.

Does the blower motor operate?

--

Go to Step 25

Go to Step 26

25

Replace the HVAC Control Assembly. Refer to Control Assembly Replacement .

Is the replacement complete?

--

Go to HVAC System Check

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26

Replace the blower motor control module. Refer to Blower Motor and Fan Replacement .

Is the replacement complete?

--

Go to HVAC System Check

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