I have had to replace the head unit on one and ordered another for insurance. My rear jacks are located in such a way that the rain gutter diverters on the back corners drop water perfectly centered over the head which has the removable plastic plug allowing you to use a 3/8' ratchet to manually raise and lower the legs.
When I first saw this, I had 2 choices. Remove the diverter or protect the head covers. I just use a quart size zip lock if it's in the weather over any amount of time. I figured some moisture had to be getting into the unit-
2015 Host Mammoth triple slide w/ TorkLift Fastguns
2015 Ram 5500 SLT cab & chassis with Douglass 9' utility body