I've read through this thread and a bunch of others, to try to address the fact that the front end of my Model S (2017 75D) is very low to the ground. I'm concerned about trying to drive it to the service center. From the noise the compressor makes, it does seem that the compressor is almost dead. (It only runs for ~10 seconds, & then I get "air suspension compressor disabled -- vehicle unable to raise".)
However: there is pressure in the system -- using a tyre gauge, there's well over 50psi (the max on the gauge).
So, my suspicion is that the valve block is faulty. It's only the front end that is low to the ground; the rear is at normal height.
I'm very intrigued by a suggestion made here:
Everything you need to know about air suspension solenoid valve block
The suggestion is to swap the air lines: connect the front lines to the "rear" terminals on the valve block, and the rear lines to the "front" terminals on the block. This would help isolate a problem, perhaps (and tell me whether the valve block is indeed faulty).
My question for now: when the car is off, are all the valves closed? When I remove the air lines from the valve block, will they be under pressure?
I figure there must be valves on the air shocks as well. So, for this idea to work, the valves on the shocks would have to be default closed (to ensure the air lines are not under pressure).
Please comment if you can help!