I need to figure out how to raise the suspension on my 1990 Coupe De Ville. Is there a switch underneath the car, in the trunk or other place?
Low Rear Suspension on 1990 Cadillac DeVille
It sounds like you automatic level ride system in not working. The fault could be an air leak in the system, a faulty compressor, a faulty height sensor, or a wiring issue. The compressor is under the hood and the height sensor is located under the rear of the car.