GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Isuzu 🢒 1999 🢒 Isuzu MD Steel Tilt (F Model) 🢒 Body and Accessories 🢒 Lighting Systems 🢒 Instrument Panel Lamps Inoperative

Instrument Panel Lamps Inoperative Dimming Lamps Inoperative

Step

Action

Value(s)

Yes

No

1

Place the headlamp switch in the PARK position.

Are the tail lamps ON?

--

Go to Step 11

Go to Step 2

2
  1. Remove the taillamp relay from the socket.
  2. Connect a J 39200 between socket terminal 85 and ground.

Does the DMM indicate voltage?

12V

Go to Step 4

Go to Step 3

3

Locate and repair the open in CKT 93 (GRN) to the tail lamp relay.

Is the repair complete?

--

System OK

--

4

Connect a J 39200 between socket terminal 86 and chassis ground.

Did the DMM indicate continuity?

--

Go to Step 5

Go to Step 6

5

Replace the tail lamp relay.

Is the repair complete?

--

System OK

--

6

Connect an ohmmeter between headlamp switch terminal 2 and chassis ground.

Did the ohmmeter indicate continuity?

--

Go to Step 7

Go to Step 8

7

Locate and repair the open in CKT 85 (GRN/WHT).

Is the repair complete?

--

System OK

--

8

Connect an ohmmeter between headlamp switch terminal 1 and chassis ground.

Did the ohmmeter indicate continuity?

--

Go to Step 10

Go to Step 9

9

Locate and repair the open in the ground wire 4 (BLK) between G105 and terminal 1 in the headlamp switch.

Is the repair complete?

--

System OK

--

10

Replace the headlamp switch.

Is the repair complete?

--

System OK

--

11
  1. Turn the headlamp illumination control counter clockwise to the dimmest position.
  2. Remove the buss connector from the IP lamp dimmer buss.
  3. Connect a test lamp between terminal A and chassis ground.

Does the test lamp light?

--

Go to Step 12

Go to Step 13

12

Replace the IP lamp dimmer buss .

Is the repair complete?

--

System OK

--

13
  1. Connect a jumper between terminal A in the IP lamp dimmer buss connector.
  2. Disconnect the 17-way harness connector from the IP cluster.
  3. Connect a J 39200 between connector C3, terminal 2 in the 17-way IP harness connector and chassis ground.

Does the DMM indicate continuity?

--

Go to Step 15

Go to Step 14

14

Repair the open in CKT 3 (BLK/RED) between terminal A in the IP lamps dimmer buss connector and terminal 2 in the 17-way IP cluster harness connector.

Is the repair complete?

--

System OK

--

15

Connect a test lamp between connector C1, terminal 1 in the 17-way IP cluster harness connector and chassis ground.

Does the test lamp light?

--

Go to Step 17

Go to Step 16

16

Repair the open in CKT 2 (BRN) between S272 and connector C3, terminal 1 in the IP cluster harness connector.

Is the repair complete?

--

System OK

--

17
  1. Disconnect the 15-way IP cluster harness connector.
  2. Connect a test lamp between connector C1, terminal 9 in the IP cluster harness connector and connector C3, terminal 1 in the 17-way IP cluster harness connector.

Does the test lamp light?

--

Go to Step 18

Go to Step 19

18

Replace the IP cluster.

Is the repair complete?

--

System OK

--

19

Locate and repair the open in the ground CKT 4 (BLK) between G105 and connector C1, terminal 9 in the IP cluster harness connector.

Is the repair complete?

--

System OK

--

Instrument Panel Lamps Inoperative Always at Full Brightness

Step

Action

Value(s)

Yes

No

1
  1. Set the headlamp switch to the OFF position.
  2. Disconnect the 17-way IP cluster harness connector.
  3. Remove the buss connector from the IP lamps dimmer buss.
  4. Using a J 39200 DMM connected to chassis ground, probe each terminal inside joint connector 3 (upper).

Does the DMM indicate continuity in any of the probed joint connector terminals?

--

Go to Step 2

Go to Step 3

2

Locate and repair the short to ground in the affected circuit.

Does the illumination control dim the instrument panel lamps?

--

System OK

--

3

Replace the IP Cluster.

Does the illumination control dim the instrument panel lamps?

--

System OK

--