What kind of lock do I need to lock this sliding door from the outside?
http://www.prioritydoorwindow.com/wp-content/uploads/2015/09/Aluminum_Products.pdf suggests that keyed locks are only an option on the Fleetwood 3000/3000-T line, not the 1000 line (which is the only one that is not named &quot;luxury&quot;).
I don't know how to tell the model, but it looks like the 1000 series doesn't have keyed locks as a manufacturer option.  If you do have 3000/3000-T, could see if they offer it as as a replacement SKU.
I've not heard of third-party locks for this kind of equipment, but maybe someone else will have some other ideas.