I have a 1999 Holiday Rambler Vacationer with a Ford V10 which I purchased in January. I just returned from a 2500 mile trip to Montana and experienced the water ingestion problem during the trip. After talking to the Ford RV hotline (1-800-444-3311) and reading many posts on the internet regarding the subject, I decided on my own fix. One person said he had the Ford adapter installed on his RV and still experienced the water ingestion problem. Another person was on a trip and experienced the same problem and for a temporary fix, used a piece of sewer hose or clothes dryer hose over the air intake tube and ran it up to the top of the hood area and secured it with tie straps and has not experienced the water ingestion problem for over 2 years.
I decided to do the same, as Ford wanted $108 for the adapter, so I attached a piece of 3" sewer hose to the air intake duct and secured it with a hose clamp. Then I secured the other end of the hose to the top of the hood area with a tie strap and bought a 3" plastic patio drain cover and secured it to the end of the sewer hose with another hose clamp. This solved the problem of animals crawling into the hose and nesting etc during the times I have the rig parked.
I hope this helps some of you.