Wow!
On the roof, Vito has no idea but I replaced the two Honeywell switches. The tops were deteriorated. Not easy but bought spares a while ago.
I checked all the wiring. The control unit is way over-enginered. They run major industrial operations with it.
I went back to the original computer also and the USB connections. This has 8.1 ACP on it.
It has cycled 4 times OK this AM via ACP.
Almost as bad a taking care of an aircraft...