With the towbar loose, and the toad out of the way, Just try to push the end of the bar in. if it is locked, it won't move. Do this on both sides. If it pushes in, then just pull it all the way out and see if the levers pop up and it locks. Check both sides. To lock, the bars have to be all the way extended, so it not unusual for them both not to lock until you turn enough to get both extended. If they both pass the pulling them out test, then after hooking up, an "S" turn should let both lock. On mine, many times neither one is locked until I pull forward, and usually I can feel it from the drivers seat when each locks.
Noel, Betty, one fuzzy little poodle that thinks he is a standard
2005 Gulfstream Ultra Supreme 30' 07 HHR Toad