HouseCallAuto 9/10/2012No diagrams here. Question: Do you hear the air compressor turn on AT ALL? If not >>
1. Verify the main 30A fuse in the engine compartment fuse box is present and has battery voltage on both sides.
2. If the fuse is OK, go to the air suspension module in the trunk. Ground pin 23 Dark Blue/Yellow (DB/YE) and verify the compressor relay in the engine compartment fuse box clicks and that the compressor runs.
3. If the relay clicks, but the compressor doesn't run, check for battery voltage to the compressor on the Purple/Orange (P/O) wire with the DB/YE still grounded.
4. If battery voltage is present on the P/O wire, check for a ground on the Black (BK) wire. If power and ground are both OK, but the compressor is not running, replace the compressor and retest.