Simple enough to check. If the compressor does not cycle when you turn the key on, then the air bags are not being properly inflated/charged. You should be able to hear the compressor run as soon as you turn on the key. (engine does not need to be running). It is quite possible that 1) your compressor is shot and will not start, 2) the bags have developed leaks in them, or 3) the level control actuator is not set properly. Most likely it is the compressor, a simple fix, but $pricey. I recommend replacing the air bag/compressor setup with a couple of coil springs for a Grand Marquis from your local Auto Zone. Mine cost $69 plus tax, and about an hour to install. Just jack up the rear of the car, disconnect the clip from the top of the air bag/bladder, diconnect the air lines and electrical connector to the bag, and with the car jacked up, slip the coils and their respective seats in place of the bags. Some will tell you that it "doesn't have that ride on air" feeling anymore, I for one find that is BS, car rides just great, certainly better than it did with leaky bags in it. Oh, one other thing, if it is a '98 or newer, the air suspension light on the dash will stay on . I learned to live with it. I can always re-install the bags and purchase a new ($300) compressor at a later date if I wish... NOT
