GM Service Manual Online
For 1990-2009 cars only

Problem

Action

Obstruction in the defroster duct

    • Inspect the defroster duct. Refer to Defroster Air Outlet Replacement .
    • Remove any foreign objects.
    • Repair any loose instrument panel pad that blocks an outlet.

Faulty defroster air valve vacuum actuator or hose

    • Inspect the defroster air valve operation.
    • Replace the defroster actuator or hose. Refer to Defroster Valve Actuator Replacement in HVAC - Manual.

Insufficient heat

Refer to Heating Insufficient .