Front defroster does not work

PAULA COOPS

MEMBER
2009 PONTIAC VIBE
205,000 MILES

I have heat, air and my back defroster works, but my front defroster does not work in my car. The heat blows great and my air blows great. When I turn the knob to go to my defroster, it does not switch over and the heat just blows out of the front vents. It does not work when I turn the knob to blow on my feet, it continues to blow out of the front vents. The heat gets very hot and the air gets very cold and they work wonderful. I just can’t get it to defrost or blow on my feet.

1 Reply

JACOBANDNICKOLAS

MECHANIC
109,885 POSTS

Hi,

Airflow direction is controlled by a mode door actuator. On this vehicle, it is changed by a cable. I suspect it is out of adjustment or one of the connectors has broken.

I am going to provide the directions for the replacement of the cable. I'm not saying it needs to be replaced, but the directions show how it is adjusted toward the end.

The attached pics correlate with the directions.

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2009 Pontiac Vibe FWD L4-2.4L
Mode Control Cable Replacement
Vehicle Heating and Air Conditioning Air Door Air Door Cable Service and Repair Removal and Replacement HVAC - Manual Mode Control Cable Replacement
MODE CONTROL CABLE REPLACEMENT
Mode Control Cable Replacement

Removal Procedure

1. Remove the HVAC control assembly. Refer to Heater and Air Conditioning Control Replacement (See: Control Assembly, HVAC > Removal and Replacement > Heater and Air Conditioning Control Replacement).

See pic 1

Important: Note the routing of the cable to make installation easier.

2. Using a taped flat-bladed tool, disengage the clip and disconnect the mode control cable from the HVAC module assembly.
3. Remove the mode control cable from the vehicle.

Installation Procedure

pic 2

1. Position the mode control cable in the vehicle. Route the cable as previously noted.
2. Position the gear (1) of the mode control cable (2) and the unit link to the HVAC module assembly.
3. Install the HVAC control assembly. Refer to Heater and Air Conditioning Control Replacement (See: Control Assembly, HVAC > Removal and Replacement > Heater and Air Conditioning Control Replacement).

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Let me know if this helps or if you have other questions.

Take care,
Joe

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