Dash Air Vents Stay in Defrost Position (Older Cars)
Step by step guide on how to repair air vents that stay in the defrost position,
this article pertains to older vehicles using a vacuum operated heater/air conditioner
Difficulty Scale: 3 of 10
Tools and Supplies Needed
Protective eye wear and clothing
Rubber vacuum line
Before you begin, park the car on level ground, with the emergency brake set,
Step 1 - Older heater/defroster systems use a vacuum
hose that supplies a control valve in the climate control panel with vacuum, this
hose can break due to the extreme heat of the engine compartment.
Lift your hood and inspect the vacuum hose or tube that leads from the engine
intake manifold or vacuum supply manifold to the passenger's side firewall.