Hummer H2. Manual - part 326

TURN SIGNAL LAMPS AND/OR INDICATORS ALWAYS ON OR FLASHING 

Turn Signal Lamps and/or Indicators Always On or Flashing 

3

Are all the stop lamps inoperative?

Go to Step 6

Go to Step 4

4

Test the supply voltage circuit of the inoperative lamp 
for high resistance, an open, or a short to ground. 
Refer to Circuit Testing and Wiring Repairs in 
Wiring Systems. 
Did you find and correct the condition?

Go to Step 12

Go to Step 5

5

Test the ground circuit of the inoperative lamp for 
high resistance or an open. Refer to Circuit Testing 
and Wiring Repairs in Wiring Systems. 
Did you find and correct the condition?

Go to Step 12

Go to Step 8

6

Test the battery positive circuit of the stoplamp 
switch for high resistance, an open or a short to 
ground. Refer to Circuit Testing and Wiring 
Repairs in Wiring Systems. 
Did you find and correct the condition?

Go to Step 12

Go to Step 7

7

Test the stop lamp switch signal circuit of the 
stoplamp switch for a short to ground, high resistance 
or an open. Refer to Wiring Repairs in Wiring 
Systems. 
Did you find and correct the condition?

Go to Step 12

Go to Step 9

8

Inspect for poor connections at the harness connector 
of the bulb or high mount stop lamp. Refer to Testing 
for Intermittent Conditions and Poor Connections 
and Connector Repairs in Wiring Systems. 
Did you find and correct the condition?

Go to Step 12

Go to Step 10

9

Inspect for poor connections at the harness connector 
of the switch. Refer to Testing for Intermittent 
Conditions and Poor Connections and Connector 
Repairs in Wiring Systems. 
Did you find and correct the condition?

Go to Step 12

Go to Step 11

10

Replace the stop lamp. Refer to Tail/Turn Signal 
Lamp Replacement (SUV) or High Mounted Stop 
Lamp Replacement (SUV) . 
Did you complete the replacement?

Go to Step 12

-

11

Replace the stop lamp switch. Refer to Stop Lamp 
Switch Replacement . 
Did you complete the replacement?

Go to Step 12

-

12

Operate the system in order to verify the repair. 
Did you correct the condition?

System OK

Go to Step 3

Step

Action

Yes

No

Schematic Reference: Exterior Lights Schematics 

 

2004 Hummer H2 

2004 ACCESSORIES & EQUIPMENT Lighting Systems - Hummer H2

  

Connector End View Reference: Lighting Systems Connector End Views or Body Control System 
Connector End Views in Body Control System.

1

Did you perform the Lighting Diagnostic System 
Check?

Go to Step 2

Go to Diagnostic 

System Check - 

Lighting Systems

2

1. Turn ON the ignition, with the engine OFF.  

2. Operate the turn signal switch in both the left 

and right hand turn signal positions.  

Does the turn signal system operate normally?

Go to Testing for 

Electrical 

Intermittents in 

Wiring Systems

Go to Step 3

3

Test the appropriate turn signal bulb supply voltage 
circuit for a short to voltage. Refer to Circuit Testing 
and Wiring Repairs in Wiring Systems. 
Did you find and correct the condition?

Go to Step 10

Go to Step 4

4

1. Disconnect the turn signal/hazard flasher 

module.  

2. Connect a test lamp between the appropriate turn 

signal switch signal circuit terminal of the turn 
signal/hazard flasher module connector and a 
good ground.  

Does the test lamp illuminate?

Go to Step 5

Go to Step 6

5

Test the appropriate turn signal switch signal circuit 
for a short to voltage. Refer to Circuit Testing and 
Wiring Repairs in Wiring Systems. 
Did you find and correct the condition?

Go to Step 10

Go to Step 7

6

Inspect for poor connections at the harness connector 
of the turn signal/hazard flasher module. Refer to 
Testing for Intermittent Conditions and Poor 
Connections and Wiring Repairs in Wiring Systems.
Did you find and correct the condition?

Go to Step 10

Go to Step 8

7

Inspect for poor connections at the harness connector 
of the turn/hazard switch. Refer to Testing for 
Intermittent Conditions and Poor Connections and 
Wiring Repairs in Wiring Systems. 
Did you find and correct the condition?

Go to Step 10

Go to Step 9

8

Replace the turn signal/hazard flasher module. 
Did you complete the replacement?

Go to Step 10

-

9

Replace the multifunction, turn signal and hazard 
switch. Refer to Multifunction, Turn Signal Switch 
Replacement in Steering Wheel and Column. 
Did you complete the replacement?

Go to Step 10

-

10

Operate the system in order to verify the repair. 
Did you correct the condition?

System OK

Go to Step 3

 

2004 Hummer H2 

2004 ACCESSORIES & EQUIPMENT Lighting Systems - Hummer H2

  

TURN SIGNAL LAMPS AND/OR INDICATORS INOPERATIVE

Turn Signal Lamps and/or Indicators Inoperative 

Step Action

Yes

No

Schematic Reference: Exterior Lights Schematics 
Connector End View Reference: Lighting Systems Connector End Views or Body Control System 
Connector End Views in Body Control System.

1

Did you perform the Lighting Systems Diagnostic 
System Check?

Go to Step 2

Go to Diagnostic 

System Check - 

Lighting 

Systems

2

Verify that the turn signal lamps and/or indicators are 
inoperative. 
Do the turn signal lamps and/or indicators operate 
normally?

Go to Testing for 

Intermittent 

Conditions and Poor 

Connections in Wiring 

Systems

Go to Step 3

3

Are only the turn signal indicators in the instrument 
panel cluster (IPC) inoperative?

Go to Step 4

Go to Step 5

4

Test the inoperative turn signal supply voltage circuit to 
the IPC for an open or high resistance. Refer to Circuit 
Testing and Wiring Repairs in Wiring Systems. 
Did you find and correct the condition?

Go to Step 21

Go to Step 13

5

Is only one turn signal lamp inoperative?

Go to Step 6

Go to Step 8

6

Inspect the inoperative bulb/socket for an internal short, 
poor terminal contact, or an open filament. 
Was a problem found?

Go to Step 18

Go to Step 7

7

Test for an open, high resistance, or short to ground in 
the turn signal lamp supply voltage circuit. Refer to 
Circuit Testing and Wiring Repairs in Wiring 
Systems. 
Did you find and correct the condition?

Go to Step 21

Go to Step 16

8

Inspect the IGN E fuse and the FLASHER fuse. 
Is either fuse open?

Go to Step 11

Go to Step 9

9

Test for an open or high resistance in the following 
circuits: 

z

The turn/hazard flasher battery positive supply 
voltage  

z

The turn/hazard flasher ground  

z

The turn signal switch ignition 1 supply voltage  

 
Refer to Circuit Testing and Wiring Repairs in 
Wiring Systems. 
Did you find and correct the condition?

Go to Step 21

Go to Step 10

 

2004 Hummer H2 

2004 ACCESSORIES & EQUIPMENT Lighting Systems - Hummer H2

  

10

1. Disconnect the multifunction switch, turn signal 

switch.  

2. Test the multifunction turn signal switch for 

continuity between the multifunction turn signal 
switch ignition 1 voltage input terminal and the 
turn signal flasher signal output terminal in each 
respective position. Refer to Circuit Testing in 
Wiring Systems.  

Is continuity present?

Go to Step 12

Go to Step 14

11

Test the following circuits for a short to ground: 

z

The multifunction turn signal switch ignition 1 
voltage  

z

The turn/hazard flasher supply voltage  

z

The left turn signal switch signal  

z

The right turn signal switch signal  

z

The left turn signal lamps supply voltage  

z

The right turn signal lamps supply voltage  

z

The trailer left rear turn/stop lamp supply voltage 

z

The trailer right rear turn/stop lamp supply 
voltage  

 
Refer to Circuit Testing and Wiring Repairs in 
Wiring Systems. 
Did you find and correct the condition?

Go to Step 21

Go to Step 14

12

Test the following circuits for an open or high 
resistance: 

z

The multifunction turn signal switch ignition 1 
voltage  

z

The turn/hazard flasher supply voltage  

z

The left turn signal switch signal  

z

The right turn signal switch signal  

z

The left turn signal lamps supply voltage  

z

The right turn signal lamps supply voltage  

z

The trailer left rear turn/stop lamp supply voltage 

z

The trailer right rear turn/stop lamp supply 
voltage  

 

 

2004 Hummer H2 

2004 ACCESSORIES & EQUIPMENT Lighting Systems - Hummer H2