Exterior basement locks

[Nonnaof Two]

When I was handed the keys to my 2014 Fleetwood Excursion 33A a few weeks ago with not much direction I thought oh well not so hard. Wrong! After about two hours last night of trying all the keys until I found what key unlocked each lock. The last key for the exterior basement doors don't really work. The key has a hard time going in the slot. If it does go in it doesn't turn. I know I had them open before because I have stuff in there but now I can't open them. I do try a little graphite not really helping does anyone have any information that might help. It seems like a small thing, but I can't to my sewer water and electric. Thanks everyone.
Judy

[pointrow]

Any oil or lubricant will help. Put on key and insert it several times. A little goes a long way.

[ga traveler]

The most common key for basements is 751. We were a Fleetwood dealer and they used the door key on a lot of their basement doors.
not the deadbolt key but the regular door key. Make sure you are putting the key in correctly. The uncut side goes to the center of the lock and the cut side goes to the outer edge. Some of the locks had a tiny number stamped on them. Look closely for a tm314 or similar number on the lock. It will be on the shiny center of the lock where the key goes in. You can also look in the nice folder that came in the motorhome. There is usually a page that gives all the key numbers and which lock they fit.