Both Heated Windshields Inoperative - Hummer H1 Service Manual

12-92 Electrical System
Step
1 Gain access to the heated windshield connections.
Using a DVOM check the resistance to ground on
the black wires at both windshields. Does the
resistance meet the specified value?
2 Remove the heated windshield switch from the
bezel. Turn the ignition switch to the "RUN"
position and turn the heated windshield switch to
the "ON" position. Using a DVOM check the
voltage drop between the brown wire (CKT 580)
and the black wire (CKT 58). Is the specified volt-
age present?
3 Using a DVOM measure the resistance to ground on
the black wire (CKT 58) at the heated windshield
switch. Does the resistance meet the specification?
4 With the ignition in the "RUN" position and the
heated windshield switch in the "ON" position.
Use a DVOM to check for voltage at both tan
wires (CKT 83) at the heated windshield switch.
Is the specified voltage present?
4-1-00
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Both Heated Windshields Inoperative

Action Value(s) Yes
<.2 Ω
Go to step 2.
12v Repair the open
or bad connection
in CKT 580
between the
heated wind-
shield switch and
the relays.
<.2 Ω
Go to step 4.
12v Replace the
heated wind-
shield switch.
®
No
Repair the open
or bad connection
in CKT 59
between the
windshields and
G4.
Go to step 3.
Repair the open
or bad connection
in CKT 58
between the
heated wind-
shield switch and
G4.
Repair the open
or bad connec-
tion in CKT 83
between the
windshield
switch and fuse
1C interior.