This whole debacle with the Curt controller is rather absurd yet also confusing. I'm not entirely convinced that the Curt controller is the sole issue. It's puzzling that Curt represented to FR that the controller was water resistant
. Yet the installation instructions that were affixed to my replacement controller I bought from Amazon clearly stated that the module should be installed in a "protected location similar to a vehicle interior".
Personally I think failure on mine was due (at least in part) to the fact that one of the rubber gaskets on the Deutsch connector was missing. See my earlier post for a photo here.
In my case upon replacing the Curt controller module I also purchased the Deutsch connectors so that wasn't permanently modifying the MH in the event I needed to pursue a warranty claim. The Curt controller ships with quite a bit of wiring so I left the leads pretty long which allowed me to shove them up underneath the coach further than with the original Curt controller. I also spread some conductive grease on the rubber gasket and the metallic connector pins. I subsequently wrapped the Curt controller in a ziploc bag and used a bunch of packing tape to try and seal it up.
At the time I realized that my method wouldn't provide a impermeable barrier, but figured it would keep most of the moisture out. Thus far, every one of my trips has involved mountain passes and torrential rains. To date, everything still works as intended however upon returning from my most recent trip I checked the module and could easily tell there was a fair amount of moisture, now trapped by my ziploc/packing tape job. So far I've left it alone and the Curt controller is sitting in this moisture and everything is still working. I'll likely find a better solution for weatherproofing the module itself, but for the time being I've been testing it periodically to confirm operation. I also have a spare module with the proper connectors in the glove box should I need it.