Tow bar/hitch key doesn't turn

[abols610]

Hi! Maybe there's a common problem for this. It seems that my V50 has one of these detachable tow bars. Ordered the key, although it doesn't go in completely smoothly, it fits, however I can't seem to turn it. It turns just a tiny bit and then stops and the tow bar and it's locking system don't become any looser.
Could the key hole be rusty or something? Or can it be blocked it some way?
Maybe the pictures help.

[JRL]

Try loads of WD40 in the lock and gently wiggle the key to see if it eventually turns. And when I say gently I mean gently! If you get it working give it a regular spray with white grease to keep it free. You will need to grease the rest of the working parts of the hitch as well to stop rust forming. Obviously not the tow ball itself though.

To get the ball separated from the hitch after you get the lock working you may need to give it a few whacks with a hammer using a block of wood to prevent damage.