Component Testing

WARNING: This page is about a different car, the 2007 Pontiac G5 Pursuit, 2007 Pontiac G5, and 2007 Chevrolet Cobalt. However, it is still accessible from the selected car via links, so may be relevant.

Defog Switch

Ignition OFF, disconnect the harness connector C2 at the HVAC control assembly.
Test for infinite resistance between the signal terminal A8 and the ground circuit terminal A5 with the switch in the open position.
- If not the specified value, replace the HVAC control assembly.
Test for less the 2 ohms between the signal terminal A8 and the ground circuit terminal A5 with the switch in the closed position.
- If greater than the specified range, replace the HVAC control assembly

Defog Indicator

Ignition OFF, disconnect the harness C2 at the HVAC control assembly.
Install a 5-amp fused jumper wire between circuit terminal A7 and 12 volts. Install a jumper wire between the ground circuit terminal A5 and ground. Verify the defog Indicator illuminates.
- If the defog indicator does not illuminate, replace the HVAC control assembly.

Relay Test

Ignition OFF, disconnect the RDFG relay.
Test for 60-180 ohms of resistance between terminals 85 and 86.
- If the resistance is not within the specified range, replace the relay.
Test for infinite resistance between the following terminals:
- 30 and 86
- 30 and 87
- 30 and 85
- 85 and 87
- If not the specified value, replace the relay.
Install a 25-amp fused jumper wire between relay terminal 85 and 12 volts. Install a jumper wire between relay terminal 86 and ground. Test for less than 2 ohms of resistance between terminals 30 and 87.
- If greater than the specified range, replace the relay.