when converting to coils, there is a signal wire to the message center that warns a driver if there is a problem with the air suspension. Obviously there is a problem if the car has been converted to coils.
This means every time you start the car, you will either get the warning the switch is OFF(in the trunk) or to CHECK AIR SUSP message.
Many who convert will "cut" the signal wire(it's behind the glove box, to the right, slightly above the kick panel where the modules plug in) thus making it where you must re-connect that wire when you return the car to air.
Here's the proper way to convert, without making it difficult to return to air.
remove the solenoids from the air springs, un-plug them, and disconnect the air line. save them in a safe place.
remove the ride height sensors from their mounts, and un-plug them. save them with the solenoids.
unplug the compressor
behind the glove box, above the kick panel, instead of just cutting the wire, use a curved pick-tool to pull some of the wire out of the harness and leave plenty of 'extra' wire so you can easily re-connect it later(or a future owner). tape off any exposed wire to prevent grounding.
doing all of this will make the conversion easily reversible for you, or any future owners. Mention your care and steps taken to any perspective buyers.
