Probably a leak in one or more of your air bags but could be your compressor too.
Air conditioning compressor? air ride compressor? question not clear enough.
why the compressor keeps running whil the key is out is because it is trying to keep the car at the level ride height
For air ride compressor Its a 5 or 6 wire electronic relay with a heat sink mounted on the compressor bracket.
On a 1997 Lincoln Mark VIII, the air ride compressor is located in the trunk, specifically on the driver's side, near the rear wheel well. It is mounted to the body of the vehicle and is usually covered by a panel that may need to be removed for access. The compressor is responsible for maintaining the air suspension system, adjusting the ride height as needed.
The compressor will stay running only because there is a leak in the air system somewhere and the compressor is trying to play catch up.It will burn out if left to run continuously ...
Repiar the air ride, first do a air ride test with the air ride plug under the hood on the left side, next remove the plug from the compressor and reinstall if the compressor comes on the warning goes away you will need a compressor as the temp switch in the pump has failed
compressor relay
There are 4 bags on each wheel that have air pumped into them by an onboard compressor to keep the car up and level, you get a softer ride.
The compressor is located in front of the passenger side front wheel. You have to remove the right front wheel and plastic wheel housing to get to it.
Could be a leak, relay bad, does the compressor come on?
That's your compressor running for your air suspension. couple hundread dollar fix and it goes away. Just be glad it is not fords air ride. 2,000 to fix my mark viii
So far Mark does not have a truck ride set up for 2008.