how can i fix my air ride suspension on my 92 lincoln towncar?

I am curently haveing trouble with my air ride suspension on my towncar. I had a previous problem with the main fuse box and replaced that and it was running like a champ for a few days. Now the pump wont turn on so I started checking the simplest things i.e ground wires, fuses, conections, and air ride sensor all fine. I took the car to a shop and they said that there is power running to it and to replace the pump. So i bought 2 new/used compressor pumps and those don't even work. I had replaced the pump previsouly and never ran into this problem can you please help before I take a bat to the car :(