Hummer H1 (2002+). Manual — part 214

______________________________________________________

Electrical System 12-81

®

05745159

Figure 12-95: HVAC Temp Blend Door/Rear Blower

F

E

8 PIN

FUSE 7C
30A
INTERIOR

HOT IN RUN
AND START

FUSE 6C
20A
INTERIOR

HOT IN RUN
AND START

M

REAR
HVAC
BLOWER

H

L

G4

405 OR

404 YL

E4

E3

C6

346 PK

C6-C3

399 DG

C6-G1

TEMPERATURE
DOOR MOTOR

58 BK

GROUND

POSITION

SIGNAL

IGN

INPUT

G4

7

8

10

C6-J1

RESISTOR
MODULE
(62K

Ω

)

402 LB

HVAC
CONTROL
HEAD

TEMP BLEND

MOTOR CONTROL

IGN INPUT

+

REAR HVAC

BLOWER

SWITCH

9 - S 1 2 - 0 6 3

59 BK

4-1-00

12-82

Electrical System

_______________________________________________________

®

Figure 12-96: HVAC Compressor Schematic

COMPRESSOR
RELAY

86

87

85

30

FUSE 2C
10A
INTERIOR

HOT IN RUN
AND START

POWERTRAIN
CONTROL
MODULE
(PCM)

A/C

REQUEST

A/C

COMPRESSOR

ENABLE

DIODE

COMPRESSOR
CLUTCH

G1

HIGH
PRESSURE
CUTOUT
SWITCH

LOW
PRESSURE
SWITCH

438 OR

C1-39

C4-2

347 YL

HVAC
U N I T

TEMP
CUTOUT
SWITCH

C6-J8

8 PIN

H

A/C

REQUEST

439 YL

C4-5

C27-C2

C28-D5

198 TN

440 DB

C1-1

400 LG

C4-8

348 BR

HVAC
CONTROL
HEAD

AMBIENT
TEMPERATURE
SWITCH

9-S12-061

4-1-00

______________________________________________________

Electrical System 12-83

®

05745159

Windshield Wiper Motor Inoperative All Speeds

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

Ω

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 voltage
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 wiper

switch.

Repair the open

or bad connec-

tion in CKT 65

between the

wiper switch

and fuse 7G.

Windshield Wiper Motor Inoperative on LOW

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
set to measure voltage, back probe the green wire
(CKT 63). Is the specified voltage present?

12v

Go to step 3.

Go to step 2.

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 7G.

3

Gain access to the wiper motor connector behind
the windshield trim. Using a DVOM set to mea-
sure voltage, backprobe the dark green wire (CKT
63). Turn the ignition switch to the “RUN” posi-
tion, and set the wiper switch to “LOW”. Is the
specified 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.

4-1-00

12-84

Electrical System

_______________________________________________________

®

Windshield Wiper Motor Inoperative on High

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 7G.

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 volt-
age at the red wire (CKT 61). Is the specified volt-
age 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

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.

2

Remove the wiper switch from the instrument
panel. Disconnect the wiper switch from the har-
ness.Using a DVOM measure resistance between
terminals 2 and 3. Is the resistance below the
specified value?

<.2

Ω

Connect the

intermittent

wiper switch to

the harness.

Go to step 3.

Replace the

wiper switch.

3

Turn the ignition switch to the “RUN” position
and the intermittent wiper switch to “MEDIUM
DELAY” . Using a DVOM set to measure volt-
age, back probe the brown wire (CKT 945) at the
intermittent switch. Voltage should pulse from 12
volts to 0 volts every 2-7 seconds depending on
position of switch. Is the voltage in the specified
range.

12v pulse

2-7 seconds

Go to step 5.

Go to step 4.

4-1-00