What specific problem do you have?
If You have a slow leak in a bag, line or connector. You can raise the rear (for off-road purposes) by pushing the button on the dash.
Do that, shut off the engine and then see if you can find where the air is leaking from. Maybe smoke a cigar while you are at it and see if the smoke swirls anywhere if can't hear the air escaping.
The compressor is running constantly because it's trying to play keep up with the leak while keeping the rear level.
1. Get a spray bottle, put some baby shampoo or dish washing liquid and water in it.
2. Spray the mixture over each part of the air suspension components seperatly.
3. Watch for bubbles.
I would recommend to do one component at a time so you can realy analyze each part to see if there is a leak. Spray the mixture everywhere and heavy.
If you have a leak you will most likely find it.