If you have a deadlock, hooklock or slamlock on your vehicle, it is important to keep them well maintained.
At this time of year especially, locks can be subject to road grime in the mechanisms, which can affect normal functionality. It is a good idea to use a lubricant on the lock once a month.
Choose a lubricant which is fit for purpose, as some can dry out the locks and worsen the issue. GT85 with PTFE is recommended.