Congratulations on the new trailer; it's exciting to finally get what you ordered some time ago.
Here is a
link to a PDI checklist on this site.
The dealership needs not only to show you how everything works, but to also give you time to do a thorough inspection of your new trailer. This is the Pre Delivery Inspection. Take your time; it may take a couple of hours to do it thoroughly. Be sure to take a flashlight for the dark corners.
The dealer needs to fix anything that needs attention, before you hand over money. That's what the PDI is for.
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There's lots of advice and information in forums... sometimes it is correct. For example, all of my posts are made by a political appointee who got the job as a reward for contributions to my diesel bill.
2011 Jayco 28.5RLS; 2021 Chevy Duramax; Pullrite Superglide Hitch