4
Remove the rear defog relay. Refer to
Relay Replacement (Attached to Wire
Harness) or Relay Replacement
(Within an Electrical Center) .
Did the rear window defog turn OFF?
Go to Step 5
Go to Step 8
5
Test for a voltage signal at the rear defog
relay control circuit terminal for the rear
defog relay in the underhood fuse block.
Refer to Electrical Center Identification
Views and Circuit Testing .
Was a voltage signal present?
Go to Step 7
Go to Step 10
6
Test for a short to ground in the rear
defogger switch signal circuit. Refer to
Circuit Testing and Wiring Repairs .
Did you find and correct a condition?
Go to Step 12
Go to Step 11
7
Inspect for poor connections at the harness
connector of the body control module
(BCM). Refer to Circuit Testing and
Wiring Repairs .
Did you find and correct a condition?
Go to Step 12
Go to Step 9
8
Repair the short to voltage in the rear
defog element supply voltage circuit.
Refer to Wiring Repairs .
Did you complete the repair?
Go to Step 12
-
9
Replace the BCM. Refer to Control
Module References for replacement,
setup and programming.
Did you complete the replacement?
Go to Step 12
-
10
Replace the rear defog relay. Refer to
Relay Replacement (Attached to Wire
Harness) or Relay Replacement
(Within an Electrical Center) .
Did you complete the repair?
Go to Step 12
-
11
Replace the HVAC control module. Refer
to Control Module References for
replacement, setup and programming.
Did you complete the repair?
Go to Step 12
-
1. Use the scan tool in order to clear
2007 Hummer H3
2007 ACCESSORIES & EQUIPMENT Fixed and Moveable Windows - H3