For 1990-2009 cars

### Plenum Water Flow Direction and Cleaning

A large percentage of water will flow off the windshield area into the plenum chamber drain system and then down the outside on the plenum to the underside of the vehicle. To ensure that the plenum chamber water management system performs properly, the air inlet grille panel, plenum chamber, and drains must not be blocked with debris.

In the graphic below the gray arrows show the water flow direction in the plenum chamber and drains system.

### Plenum Chamber and Drain Valve-Cleaning

The plenum chamber is located in front of the windshield and below the air inlet grille panel.

1. Remove the air inlet grille panel. Refer to Air Inlet Grille Panel Replacement.
2. Clean the plenum chamber, drains and the air inlet grille panel of debris blockage.
3. Flush the plenum chamber, drains and the air inlet grille panel with clean water.
4. Install the air inlet grille panel. Refer to Air Inlet Grille Panel Replacement