Hummer H1 Service Manual page 858

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Windshield Wipers Intermittent Speeds Inoperative (Continued)
Step
4 Ignition should be in the "RUN" position. Using a
DVOM set to measure the voltage, back probe the
yellow wire (CKT 65) at the intermittent wiper
switch. Is the specified voltage present?
5 Remove the intermittent wiper relay from the
fuse box. Turn the ignition switch to the "RUN"
position. Using a DVOM measure voltage drop
between cavity B1 (CKT 945) and cavity C3
(CKT 59). The voltage should pulse from 12 volts
to 0 volts every 2 to 7 seconds. Is the voltage in
the specified ranges?
6 Using a DVOM set to measure resistance, mea-
sure resistance to ground at cavity C3 (CKT 59)
of the fuse box. Is resistance below specification?
7 Turn the ignition to the "RUN" position. Use a
DVOM to measure voltage drop between cavity
C1 (CKT 65) and cavity C3 (CKT 59). Is the
specified voltage present?
8 With the ignition switch in the "RUN" position
and the wipers on "LOW", check the voltage drop
between cavity C2 (CKT 28) and cavity C3 (CKT
59). Does the voltage switch from 12 volts to 0
volts as the wiper completes its cycle?
9 Gain access to the wiper motor connection. Back
probe the black wire (CKT 65) with the positive
lead, and the brown wire(CKT 59) with the nega-
tive lead. With the ignition on is the voltage drop
in the specified range?
05745159
Action
Electrical System
Value(s) Yes
12v Replace the
intermittent
wiper switch.
12v pulse Go to step 7.
2-7 seconds
<.2 Ω
Repair the open
or bad connec-
tion, in CKT
945 between the
intermittent
wiper switch
and the intermit-
tent wiper relay.
12v Go to step 8.
0v – 12v – 0v Replace the
intermittent
wiper relay.
12v Replace the
wiper motor.
12-85
No
Repair the open
or bad connec-
tion in CKT 65
between the
intermittent
wiper switch
and fuse 7G.
Go to step 6.
Repair open or
bad connection
in CKT 59
between the
intermittent
wiper relay and
G4.
Repair the open
or bad connec-
tion in CKT 65
between fuse
7G and the
intermittent
wiper relay.
Go to step 9.
Repair the open
or bad connec-
tion in CKT 65
between the
wiper motor and
fuse 7G
4-1-00