[Richard]

The problem is solved, this is more for entertainment and something to check. 

The leveling system on 512 had exhibited an intermittent issue as long as we have owned it. The system would go into Level mode but the travel valves would still be energized. So as you tried to level the coach, the HCVs would try to move it back to travel height. This problem would come and go. 

Last year it came but did not go. I sent the whole control box back to HWH, and they "fixed" it. The cost was reasonable, and it worked. For a while. On our 2018 tour, it went back to it's craziness, and finally would not even go into travel mode. I hot wired the travel solenoids to get us home. 

In the fall of 18 I sent the box back for it's second trip to HWH. I installed it and it worked as it should. In mid January, it went back to it's crazy ways. 

So, I sent it back a third time. It worked when it came back, and two weeks later, the demon has returned. There is a story in here somewhere about an engineer's definition of insanity. 

If you know me, you can figure that during all of this I am poking prodding measuring and experimenting to see if I can fix it or at least understand the issue. 

Before sending it a fourth time. I have the box and boards completely disassembled on the search for a poor or damaged solder joint. I find some iffy stuff but no smoking gun. 

Today, while on the phone with HWH, checking all manner of things, cause they are scratching their heads too, I am measuring voltages on the main fuses into the board. The voltages check out on tops of the fuses, but on one of the fuses the base where the fuse plugs in doesn't read a voltage like it should. 
   

Yep the fuse was good, but not making good contact with the fuse holder. You can see the char mark on the lower leg. I suspect it was removed and checked each time the box went back to HWH. The removal process restoring decent contact, until the Florida humidity had time to corrode the connection again. New fuses were installed with anti corrosive goop. All is well. 

Something to look for when searching for electrical demons.

[pairodice]

Is this something a non-electronic Guru, such as yourself, can attempt? I need to spend some time figuring all the air systems out as our system generally works but sometimes does iffy things (I know, what ‘iffy’ things) - the coach stays level most of the time if I manually level it and then turn the whole thing off. If I use automagic leveling the coach levels front to rear but side to side it will lean to the driver side, I left it on for a while last night testing the auto leveling and it never pulled the driver side up to level. Maybe my leveling valves are off a little...
My next venture is to replace the PPVs but have to be able to get the coach off the ground to do so.
I also need to address the air leak in the sewer system that I never got to while at Tom’s place.

[Fulltiming]

The level in automatic mode is controlled by a round disc located near the center of your coach in one of the bays (mine is in the largest pass through bay) hanging from the ceiling of the compartment. If it gets out of adjustment, the system will think it is level when it is not and vice versa. Most of us don't leave it in automatic mode after it levels because a leak down will cause the AC air compressor to run way too much. The leveling system really works best with the engine running so the engine mounted air compressor can supply the needed air. It takes over 90 psi on my coach to raise a side or an end of the coach and that is right at the shut off point for the AC air compressor while the engine mounted air compressor will easily pass 120 psi.

[pestes]

Adrian - when the driver's side is still low, does the HWH "think" it is level? Are all of the low side LEDs off on the control pad?