Should be able to crank it back up using the crank handle you should have somewhere in your basement. It is extended or retracted by cranking the rod under the right slide. You will probably have to extend the slide or use a ratchet. The tire is hanging on a cable attached to the center of the tire rim, it is cranked up and down on a spool. It must have backed off some way.
2014 Cedar Creek 34 RLSA-7
2015 Chevy Silverado 3500HD LTZ SRW