It is normal for the a/c compressor to run with the mode switch set to defrost or mix. The a/c system dries the air for more efficient defrost/defog.
I don't think so.
If it's a 97 to 98 then it's probably the Blend Door actuator that is broken. If it's the first generation Mark, 93-96 check the vacuum line under the hood that goes across the intake manifold towards the back of the motor, blend door actuator broken, heater core shot.
Probably the blend door actuator is broken, big bucks for a mechanic to fix, usually in the $2,000 range
Sounds like the Blend Door actuator, a $6.00 part but about $2,000 in labor, the dash has to be removed to do the job right.
It's your blend door actuator, big job for a $6.00 part, the dash has to be removed to access unless your mechanic is a magician.
Under the dash and in order to fix the darn thing the dash has to be removed unless there is a new technique. At the dealer the price used to be $2,200. Ouch!!
To change the blend door on a 1997 Lincoln Mark VIII, you'll need to start by removing the center console and dashboard trim to access the climate control system. Disconnect the actuator motor connected to the blend door and remove any screws or bolts securing the blend door assembly. Replace the blend door and reassemble the components in reverse order. Ensure everything is securely fastened and test the system for proper operation before finalizing the installation.
WHICH COMPRESSOR, AIR SUSPENSION OR A/C.........???
Air conditioning compressor? air ride compressor? question not clear enough.
Check the blend door actuator.
It's probably the blend door actuator, which is probably broken. The part is something like $6.00 but the install is in the $2,000 area, the dash usually has to be removed. Common problem for the 97-98 models.
The air compressor was indeed created in the 1809 by German Mark Pork. As for where did he make air compressor tank, I have no idea about it but I am happy to learn that too.