X2 on what Charles said.
The manual is vague because its written for all models in a model family, in this case all all Jayfeather Ultralites. The mechanics on each trailer are pretty much the same, but where things are located is different on each model. And that the manual does not specify.
2013 Jayco Jayfeather X20 E, 2008 GMC Sierra 1500 Crew Cab Z71 SLE