Defrost Function Test
WARNING: This page is about a different car, the 2000 Mercedes-Benz C43, 2000 Mercedes-Benz C280, 1999 Mercedes-Benz C43, and 1999 Mercedes-Benz C280. However, it is still accessible from the selected car via links, so may be relevant.
Adjust selector wheel to White range. Verify "EC" (economy) button light in A/C push button control module is off. Adjust air distribution knob to vertical (12-o'clock) position. If operation is correct, air will vent from center vents and defroster outlets. A/C compressor should be engaged. If this mode does not operate properly, perform the following tests:
- Perform all testing identified under DIAGNOSTIC TESTS .
- VACUUM TESTS under SYSTEM TESTS.