Well our air suspension problems continue on our 2004 Lincoln Navigator. First we find a damaged solenoid oring, but it continues to leak. After a good inspection we don't find anything obvious, so we try to narrow it down to either solenoid or air strut. After we replace the faulty solenoid, we have on last issue with the compressor turning on or off. Ends up being a corroded & broken relay. Now it's working properly.