Hummer H1 (2006+). Manual - part 350

12-76

Electrical System

_______________________________________________________

 HVAC Temperature Door Inoperative   (Figure 12-121)

Step

Action

Value(s)

Yes

No

1

With the ignition switch in the run position, oper-
ate temperature control dial and observe the 
motor. Does door move?

Condition is inter-

mittent.

Go to step 2.

2

Remove the temperature blend door motor from 
the side of the HVAC case. With the ignition 
switch in the run position, operate the temperature 
control dial and observe the motor. Is the motor 
turning?

Mechanical prob-

lem in the HVAC 

case.

Go to step 4.

3

Disconnect electrical connector from the temper-
ature blend door motor. Using a DVOM, set to 
measure voltage, and using J–35616-92 test 
adapters, probe the dark green wire (CKT 399) 
with the positive lead and the black wire (CKT 
58) with the negative lead. Turn the ignition 
switch to the run position. Is voltage present?

+12v

Go to step 6.

Go to step 4.

4

With ignition on, using a DVOM, set to measure 
voltage and using J–35616-92 test adapters probe 
the dark green wire (CKT 399) with the positive 
lead. Place the negative lead on a known good 
ground. Is voltage present?

+12v

Go to step 5.

Repair open or 

short to ground 

between tempera-

ture blend door 

motor and fuse 7C.

5

With the ignition off, and using a DVOM, set to 
measure ohms, check for resistance between the 
black wire (CKT 58) of the temperature blend 
door, and a good ground. Does resistance exceed 
specifications?

<.2

1

Locate open or bad 

connection between 

temperature blend 

door motor and G4.

Go to step 6.

6

Using a DVOM, set to read volts, the ignition 
switch on the run position, and using J–35616-92 
test adapters, probe the light blue wire (CKT 402) 
with the positive lead, and the black wire (CKT 
58) with the negative lead. Rotate temperature 
control dial on the HVAC control head from cold 
to hot and back. Is voltage present at the cold set-
ting and 0v on the hot setting?

Cold = +12v

Hot = 0v

Cold = +12v

Replace the temper-

ature blend door 

motor.

Go to step 7.

7

Disconnect the 8 wire connector at the HVAC 
control head. Using a DVOM, set to measure 
ohms, check resistance between the light blue 
(CKT 402) of the 8 wire connector, and the light-
blue wire (CKT 402) of the temperature blend 
door connector. Does resistance exceed specifica-
tions?

62K

1

Go to step 9.

Go to step 8.

8 

Check for open or bad connection between the 
HVAC control head 8 wire connection and the 
temperature blend door motor connection. Check 
for loose terminals at the control head. Was a bad 
connection found?

Repair or replace 
harness as neces-

sary.

Go to step 9.

______________________________________________________

 Electrical System  12-77

WINDSHIELD WIPER SYSTEM AND COMPONENTS

Windshield Wiper Motor Assembly Replacement

Removal

1.

Remove the headliner.

2.

Remove the center trim from the windshield assembly.

3.

Disconnect the windshield wiper motor assembly harness from the crossbody harness (Figure 12-56).

4.

Remove the three bolts, washers, and lock washers securing the windshield wiper motor assembly to the windshield assembly.

5.

Remove the retainer securing the windshield wiper linkage to the windshield wiper motor cranking pin and remove the wind-
shield wiper motor assembly.

Installation

1.

Lubricate the windshield wiper motor cranking pin and secure the windshield wiper linkage to the windshield wiper motor 
cranking pin using the retainer (Figure 12-56).

2.

Secure the windshield wiper motor assembly to the windshield assembly with the three lock washers and bolts. Tighten the
bolts to 12 lb-ft (16 N•m).

3.

Connect the windshield wiper motor assembly harness to the crossbody harness.

4.

Secure the windshield center trim to windshield.

5.

Install the headliner.

9

Using a DVOM, set to measure voltage, probe the 
dark green wire (CKT 399) of the 8 wire connec-
tor on the HVAC control head with the positive 
lead, and the black wire (CKT 58) of the three 
wire HVAC control head connector with the nega-
tive lead. With ignition on, is voltage present?

+12v

Replace faulty 

HVAC control 

head.

Go to step 10.

10

Using a DVOM, set to measure voltage, probe the 
dark green wire (CKT 399) of the HVAC control 
head eight wire connector with the positive lead. 
Attach the negative lead to a known good ground. 
With the ignition switch in the run position, is 
voltage present?

+12v

Go to step 11.

Locate short or 

open between the 

HVAC control head 

and fuse 7C.

11

Using a DVOM, set to measure ohms, check 
resistance between the black wire (CKT 58) of 
the HVAC control head connector and a good 
ground. Does resistance exceed specifications?

<.2

1

Replace faulty 
HVAC control 

head.

Locate and repair 

open or poor con-

nection in the 

ground circuit 

between CKT 58 

and G4.

 HVAC Temperature Door Inoperative (Cont’d)  (Figure 12-121)

Step

Action

Value(s)

Yes

No

12-78

Electrical System

_______________________________________________________

Figure 12-56:   Windshield Wiper Motor Assembly Replacement

 Windshield Wiper Motor Inoperative All Speeds  (Figure 12-158)

Step

Action

Value(s)

Yes

No

1

Gain access to the wiper motor connector under 
the windshield trim. Using a DVOM, set to mea-
sure resistance, check resistance to ground on the 
brown wire (CKT 59). Is the resistance below the 
specified value?

<.2

1

Go to step 2.

Repair open or 

bad connection 

in CKT 59 

between the 

wiper motor and 

G4.

2

Turn the ignition switch to the “RUN” position 
and the wiper switch to “LOW”. Using a DVOM, 
set to measure voltage, check for voltage at the 
dark green wire (CKT 63). Is the specified volt-
age present?

+12v

Replace the 

wiper motor.

Go to step 3.

3

Remove the wiper switch from the instrument 
panel and turn the ignition to the “RUN” position. 
Using a DVOM, set to measure voltage, back 
probe the yellow wire (CKT 65) at the wiper 
switch. Is the specified voltage present?

+12v

Replace the 

wiper switch.

Repair the open 

or bad connec-

tion in CKT 65 

between the 

wiper switch 

and fuse 13G.

 Windshield Wiper Motor Inoperative on LOW  (Figure 12-158)

Step

Action

Value(s)

Yes

No

1

Remove the wiper switch from the instrument 
panel. Turn the ignition to the “RUN” position 
and the wiper switch to “LOW”. Using a DVOM,   
back probe the dark green wire (CKT 63) at the 
switch. Is the specified voltage present? 

+12v

Go to step 3.

Go to step 2.

WINDSHIELD

LINKAGE

WINDSHIELD WIPER 
MOTOR ASSEMBLY

ASSEMBLY

WINDSHIELD WIPER 

WINDSHIELD WIPER

MOTOR CRANKING PIN

WINDSHIELD WIPER MOTOR 

ASSEMBLY HARNESS

RETAINER

______________________________________________________

 Electrical System  12-79

2

Using a DVOM, set to measure voltage, back 
probe the yellow wire (CKT 65) at the wiper 
switch. Place the ground lead on a known good 
ground. With the ignition on, is the specified volt-
age present?

+12v

Replace the 

wiper switch. 

Repair open or 

bad connection 

in CKT 65 

between the 

wiper switch 

and fuse 13G.

3

Gain access to the wiper motor connector behind 
the windshield trim. Using a DVOM, back probe 
the dark green wire (CKT 63) at the wiper motor. 
Turn the ignition switch to the “RUN” position, 
and set the wiper switch to “LOW”. Is the speci-
fied voltage present?

+12v

Replace the 

wiper motor.

Repair the open 

or bad connec-

tion in CKT 63 

between the 

wiper motor and 

the wiper 

switch.

 Windshield Wiper Motor Inoperative on High  (Figure 12-158)

Step

Action

Value(s)

Yes No

1

Remove the wiper switch from the instrument 
panel. Turn the ignition to the “RUN” position 
and the wiper switch to “HIGH”. Using a DVOM, 
set to measure voltage, back probe the red wire 
(CKT 61). Is the specified voltage present? 

+12v

Go to step 3.

Go to step 2.

2

With the ignition switch in the RUN” position, 
check the voltage at the yellow wire (CKT 65). Is 
the specified voltage present?

+12v

Replace the 

wiper switch.

Repair the open 

or bad connec-

tion on CKT 65 

between the 

wiper switch 

and fuse 13G.

3

Gain access to the wiper motor connector under 
the windshield trim. Turn the ignition switch to 
the “RUN” position and the wiper switch to the 
“HIGH” position. Using a DVOM, check the 
voltage at the red wire (CKT 61). Is the specified 
voltage present?

+12v

Replace the 

wiper motor.

Repair the open 

or bad connec-

tion on CKT 61 

Between the 

wiper motor and 

the wiper 

switch.

 Windshield Wipers Intermittent Speeds Inoperative   (Figure 12-158)

Step

Action

Value(s)

Yes

No

1

Do the windshield wipers work normally on the 
low and high speeds?

Go to step 2.

Refer to the 

diagnostic chart 

for the specific 

problem on the 

standard wiper 

diagnosis.

 Windshield Wiper Motor Inoperative on LOW  (Figure 12-158)

Step

Action

Value(s)

Yes

No