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Makes 🢒 GMC_Truck 🢒 1999 🢒 Savana 🢒 Body and Accessories 🢒 Lighting Systems 🢒 Headlamps Inoperative - One Lamp

Headlamps Inoperative - One Lamp Domestic

Step

Action

Value(s)

Yes

No

1

Was the Headlight System Check performed?

--

Go to Step 

Headlight System Check

2

Are both low and high beam headlamps inoperative?

--

Go to Step 9

Go to Step 3

3

Is the left headlamp inoperative?

--

Go to Step 4

Go to Step 13

4

Is the low beam inoperative?

--

Go to Step 6

Go to Step 5

5

Is the high beam inoperative?

--

Go to Step 8

Headlight System Check

6
  1. Connect an unpowered test lamp between the left headlamp connector cavity B for CKT 12 (TAN) and ground G108.
  2. Place the headlamp switch in the HDLP position.
  3. Place the headlamp dimmer switch in the LO position.

Does the test lamp light?

--

Go to Step 10

Go to Step 7

7

Locate and repair the open in CKT 12 (TAN) between the following components:

    • The underhood fuse relay center cavity G2
    • The left headlamp connector cavity B

Is the repair complete?

--

Headlight System Check

--

8
  1. Connect an unpowered test lamp between the left headlamp connector cavity C for CKT 11 (GRN) and ground G108.
  2. Place the headlamp switch in the HDLP position.
  3. Place the dimmer switch in the HIGH position.

Does the test lamp light?

--

Go to Step 10

Go to Step 9

9

Locate and repair the open in CKT 11 (LT GRN) between the following components:

    • The underhood fuse relay center cavity G4
    • The left headlamp connector cavity C

Is the repair complete?

--

Headlight System Check

--

10
  1. Disconnect the connector at the left headlamp.
  2. Connect a J 39200 DMM between the left headlamp connector cavity A for CKT 150 (BLK) and ground G108

Is continuity present?

--

Go to Step 11

Go to Step 12

11

Replace the left headlamp assembly.

Is the repair complete?

--

Headlight System Check

--

12

Locate and repair the open in CKT 150 (BLK) between the following components:

    • The left headlamp connector cavity A
    • Ground G108

Is the repair complete?

--

Headlight System Check

--

13

Is the low beam inoperative?

--

Go to Step 15

Go to Step 14

14

Is the high beam inoperative?

--

Go to Step 17

Headlight System Check

15
  1. Connect an unpowered test lamp between the right headlamp connector cavity B for the following components:
    2. • CKT 12 (TAN)
    • G109
  2. Place the headlamp switch in the HDLP position.
  3. Place the headlamp dimmer switch in the LO position.

Does the test lamp light?

--

Go to Step 19

Go to Step 16

16

Locate and repair the open in CKT 12 (TAN) between the following components:

    • The underhood fuse relay center cavity 12
    • The right headlamp connector cavity B

Is the repair complete?

--

Headlight System Check

--

17
  1. Connect an unpowered test lamp between the following components:
    2. • The right headlamp connector cavity C for CKT 11 (LT GRN)
    • Ground G109
  2. Place the headlamp switch in the HDLP position.
  3. Place the headlamp dimmer switch in the HIGH BEAM position.

Does the test lamp light?

--

Go to Step 19

Go to Step 18

18

Locate and repair the open in CKT 11 (LT GRN) between the following components:

    • The underhood fuse relay center cavity J4
    • The right headlamp connector cavity C

Is the repair complete?

--

Headlight System Check

--

19
  1. Disconnect the connector at the right headlamp.
  2. Connect a J 39200 DMM between the right headlamp connector cavity A for CKT 151 and ground G109

Is continuity present?

--

Go to Step 20

Go to Step 21

20

Replace the right headlamp assembly.

Is the repair complete?

--

Headlight System Check

--

21

Locate and repair the open in CKT 151 (BLK/WHT) between the following components:

    • The right headlamp connector cavity A
    • Ground G109

Is the repair complete?

--

Headlight System Check

--

Headlamps Inoperative - One Lamp Export

Step

Action

Value(s)

Yes

No

1

Was the Headlight System Check performed?

--

Go to Step 2

Go to Headlight System Check

2

Are both low and high beam functions of one headlamp inoperative?

--

Go to Step 9

Go to Step 3

3

Is the left headlamp low or high beam function inoperative?

--

Go to Step 4

Go to Step 7

4

Test the LH HI BM fuse and the LH HDLP fuse for an open condition.

Was an open condition found for any fuse?

--

Go to Step 10

Go to Step 5

5
  1. Place the headlamp switch in the Head position.
  2. Place the headlamp dimmer switch in the LO position.
  3. Disconnect the LH headlamp connector.
  4. Connect a J 39200 DMM between the left headlamp connector cavity B for CKT 12 (TAN) and ground.
  5. Measure and record voltage.
  6. Place the headlamp dimmer switch in the HI position.
  7. Connect a J 39200 DMM between the left headlamp connector cavity A for CKT 11 (LT GRN) and ground.
  8. Measure and record voltage.

Are both voltage measurements within the specified range?

12-14V

Go to Step 6

Go to Step 11

6

Test both headlamp filaments for an open condition.

Was an open condition found for any filament?

--

Go to Step 12

Go to Step 13

7

Test the RH HI BM fuse and the RH HDLP fuse for an open condition.

Was an open condition found for any fuse?

--

Go to Step 10

Go to Step 8

8
  1. Place the headlamp switch in the Head position.
  2. Place the headlamp dimmer switch in the LO position.
  3. Disconnect the RH headlamp connector.
  4. Connect a J 39200 DMM between the right headlamp connector cavity B for CKT 12 (TAN) and ground.
  5. Measure and record voltage.
  6. Place the headlamp dimmer switch in the HI position.
  7. Connect a J 39200 DMM between the right headlamp connector cavity A for CKT 11 (LT GRN) and ground.
  8. Measure and record voltage.

Are both voltage measurements within the specified range?

12-14V

Go to Step 6

Go to Step 11

9

Repair the open in the ground circuit for the inoperative headlamp assembly: Between cavity A of the headlamp connector and ground G108 for the LH assembly, or ground G109 for the RH assembly.

Is the repair complete?

--

Go to Headlight System Check

--

10
  1. Test and repair the circuit of any open fuse for the following condition: Short to ground between the underhood fuse relay center and the headlamp connector.
  2. Install a new fuse.

Is the repair complete?

--

Go to Headlight System Check

--

11

Test and repair any circuit not in the specified range for the following condition(s): Open or high resistance between the underhood fuse relay center and the headlamp connector.

Is the repair complete?

--

Go to Headlight System Check

--

12

Replace the headlamp assembly.

Is the repair complete?

--

Go to Headlight System Check

--

13

Inspect and repair the headlamp connector for loose or corroded terminals.

Is the repair complete?

--

Go to Headlight System Check

--