* Compressor Failure: The compressor is responsible for pumping air into the system. If it's failing or completely dead, it can't maintain pressure, leading to the system defaulting to its maximum height (fully raised) as a safety mechanism. The suspension light illuminates because the system detects a pressure problem.
* Air Leaks: Leaks in the air lines, suspension bags (air springs), or even at the compressor itself can cause the system to lose pressure and struggle to maintain height. The compressor will run constantly trying to compensate, eventually leading to the same outcome – fully raised and a lit suspension light. Finding these leaks can be tricky; they might be subtle hisses or even more difficult to pinpoint.
* Height Control Valve Issues: The height control valve (or a related solenoid) regulates the air pressure in the system. A malfunction here could prevent the system from properly adjusting the height, leading to it being stuck fully raised.
* Pressure Switch Failure: The pressure switch monitors the air pressure within the system. A faulty switch might give incorrect readings, making the system think there's a pressure problem even if there isn't, or fail to properly trigger the compressor.
* Relay Problems: Relays are electromechanical switches that control the power to the compressor. A bad relay won't allow the compressor to function correctly.
* Wiring Issues: Problems in the wiring harness can prevent the compressor or other components from receiving power, or prevent the system from communicating correctly.
Troubleshooting Steps:
1. Check the Compressor: Listen for the compressor running. If it's running constantly but the car's still up, there's likely a leak. If it's not running at all, it could be the compressor itself or a related electrical problem.
2. Listen for Leaks: Carefully inspect the air lines and suspension bags for any hissing sound. Use soapy water to check connections for leaks; bubbles will form where air is escaping.
3. Inspect the Wiring: Check the wiring harness for any visible damage or loose connections.
Important Note: Repairing a Hydro-Boost system can be complicated. It involves high-pressure air and potentially expensive parts. Unless you have experience working on car suspension systems, it's highly recommended to take your Town Car to a qualified mechanic specializing in older vehicles. Improper repair can lead to further damage and safety issues.
