Check you HWH leveling system for proper grounding. Here is a pic of the wire that caused me the issues.
This is in the compartment with the Hydraulic pump. This is the wiring harness part number.
The wire below the few black wires I'm holding has no insulation as it has melted off.
Blurry pic but shows the white insulation.
Mine gave basically no warning other than being slow to retract the slide this morning. I had 8000 trouble free miles under my belt with this one.
HWH has been fantastic with the telephone support. Ultimately what we found is that the unit is not grounded correctly and burned up the small grounding wired in the control circuits. They had me clamp a jumper cable to the pump housing and the other to a good ground and off she went.
They contacted Tiffin and they are sending a grounding strap. HWH is sending a new modulator and a 32 pin pigtail that I will have to solder into the old harness. I would much rather do it than take it in to be done.