Was the defogger system check performed?

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Go to Step 2

Go to Defogger System Check

1. Turn the ignition switch on.
2. Press and release the rear defogger switch.
3. Observe the defogger indicator lamp.

Is the defogger indicator lamp on?

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Go to Step 3

Go to Step 13

Using a test light, backprobe between the rear window defogger relay connector terminal C7 and ground.

Is the test light on?

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Go to Step 8

Go to Step 10

1. If the defogger on indicator lamp turns off before test is made, press and release the rear defogger switch again.
2. Using a test light, probe the rear defogger grid harness connector between CKT 293 and CKT 450.

Is the test light on?

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Go to Step 5

Go to Step 7

Repair the rear defogger grid. Refer to Grid Line Repair .

Is the repair complete?

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Go to Defogger System Check

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1. If the defogger on indicator lamp turns off before test is made, press and release the rear defogger switch again.
2. Using a test light, probe the rear defogger grid harness connector between CKT 293 and ground.

Is the test light on?

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Go to Step 4

Go to Step 9

Repair poor connection or open in CKT 450 between the rear defogger grid and G401.

Is the repair complete?

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Go to Defogger System Check

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Using a test light, backprobe between the rear window defogger relay connector terminal B5 and ground.

Is the test light on?

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Go to Step 6

Go to Step 16

Repair poor connection or open in CKT 293 between the rear window defogger relay connector terminal B5 and the rear defogger grid.

Is the repair complete?

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Go to Defogger System Check

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Check the REAR DEFOG fuse.

Is the REAR DEFOG fuse open?

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Go to Step 11

Go to Step 12

Repair short to ground in CKT 293 or CKT 1040.

Is the repair complete?

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Go to Defogger System Check

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Repair poor connection or open in CKT 1040.

Is the repair complete?

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Go to Defogger System Check

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Using a test light, backprobe between the rear window defogger relay connector terminal B7 and ground.

Is the test light on?

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Go to Step 14

Go to Step 17

1. Using a DMM set to measure voltage, connect by backprobing between the rear window defogger relay connector terminal C5 and ground.
2. While observing the DMM, press and release several times the rear defogger switch.

When cycling the rear defogger switch, does the DMM measure a voltage between B+ and 0.5V (or less)?

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Go to Step 15

Go to Step 20

Replace the A/C-heater control. Control Assembly Replacement

Is the repair complete?

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Go to Defogger System Check

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Replace the rear window defogger relay. Refer to Rear Window Defogger Relay Replacement .

Is the repair complete?

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Go to Defogger System Check

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Check the HVAC/DRL fuse.

Is the HVAC/DRL fuse open?

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Go to Step 18

Go to Step 19

Repair short to ground in CKT 241.

Is the repair complete?

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Go to Defogger System Check

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Repair poor connection or open in CKT 241.

Is the repair complete?

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Go to Defogger System Check

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Does the DMM remain reading B+ (10-14V)?

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Go to Step 21

Go to Step 25

Check for a poor connection or open in CKT 193.

Is there a poor connection or open in CKT 193?

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Go to Step 22

Go to Step 23

Repair poor connection or open in CKT 193.

Is the repair complete?

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Go to Defogger System Check

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Using a test light connected to B+, backprobe the A/C-heater control:

is the test light on?

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Go to Step 15

Go to Step 24

Repair poor connection or open in CKT 150.

Is the repair complete?

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Go to Defogger System Check

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Does the DMM remain at 0.5V, or less?

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Go to Step 26

Go to Step 23

Check for a short to ground in CKT 193.

Is there a short to ground in CKT 193?

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Go to Step 27

Go to Step 15

Repair short to ground in CKT 193.

Is the repair complete?

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Go to Defogger System Check

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