Try emailing Jayco's customer service (firstname.lastname@example.org). Include the last 8 of your VIN with your request. I have not had any issues receiving files from them with my trailer still being under warranty. I haven't requested a diagram yet, but I did receive the floor assembly blueprint when I requested the location of the holding tanks.
2005 Ford Excursion 6.8L, 3.73
2016 Eagle 324BHTS, P3, PP 3P